A panelboard RFQ should give manufacturers enough information to quote the same electrical configuration and supply scope. A request such as “three-phase, 225 A, 42 circuits” provides a starting point, but leaves important questions unanswered: the system voltage, incoming arrangement, breaker mix, conductor terminations, enclosure construction and required product certification.
When suppliers fill those gaps differently, their prices may describe different products. The differences often become visible later, during drawing approval, component purchasing or installation.
This guide explains what buyers should include before requesting a panelboard quotation, which details can remain open during preliminary pricing, and how to identify assumptions that need approval.
A panelboard RFQ should define the electrical system, panelboard and main-device ratings, circuit schedule, breaker requirements, conductor terminations, enclosure conditions and required supply scope. Include current drawings, certification requirements, quantities and delivery expectations. Identify open items and ask suppliers to state assumptions, substitutions and exclusions so quotations can be compared on the same basis.
A useful panelboard RFQ combines electrical requirements, circuit information, installation conditions and a defined manufacturing scope. It should also identify the documents and revisions on which the quotation must be based.
The information does not need to be contained in one drawing. However, the supplier should be able to understand how the panel schedule, single-line diagram, specification and installation requirements fit together.
Start by describing what you want the manufacturer to supply.
“Panelboard” may refer to an enclosure, an interior assembly or a complete product, depending on the buyer’s purchasing arrangement. State the intended scope explicitly.
| Supply scope | Information the RFQ should clarify |
|---|---|
| Enclosure and mechanical parts | Box, trim, door, deadfront, mounting provisions, finish and interface drawings |
| Panelboard interior | Bus assembly, breaker mounting system, neutral provisions, grounding provisions and included devices |
| Complete assembly | Enclosure, interior, breakers, accessories, assembly, labeling and agreed verification |
| Assembly using customer-supplied components | Supplied component list, quantities, delivery condition and responsibility for suitability |
| Repeat OEM orders | Approved configuration reference, permitted variants, order quantities and change-control requirements |
Also identify who is responsible for selecting the electrical configuration. A manufacturer quoting against approved customer drawings has a different responsibility from one asked to propose a configuration from a load schedule.
If engineering development is included, specify the expected deliverables and approval steps. Examples include a general arrangement drawing, component list, terminal information and revised panel schedule.
For the wider manufacturing workflow, see OEM Panelboard Manufacturing: From Panel Schedule to Repeat Production.
Include the destination country and the project’s governing electrical requirements. A destination alone does not define every applicable standard, certification or installation condition.
The RFQ should identify:
UL 67 is the standard used to investigate panelboards within the relevant UL product categories. The required certification must apply to the supplied product and configuration; specifying certified components alone does not establish certification of the complete assembly.
Avoid relying on broad wording such as “UL components required” when the purchasing requirement is a certified complete panelboard. State the required deliverable directly so the supplier can confirm the applicable scope.
An RFQ can be issued before every detail is finalized, provided the unresolved information remains visible.
Use a simple status column:
| Status | Meaning | Expected supplier response |
|---|---|---|
| Confirmed | The requirement is fixed for quotation | Quote against the stated requirement |
| Supplier proposal requested | The buyer wants a recommended solution | Describe the proposed selection and its basis |
| To be confirmed | Information is unavailable or awaiting approval | Identify the quotation assumption and possible impact |
| Optional | The item is outside the base configuration | Price separately and describe any dependencies |
For example, a buyer may confirm the system voltage and branch breaker schedule while asking the supplier to propose enclosure dimensions. That is a workable quotation basis.
By contrast, leaving the system voltage unspecified while requesting a firm component selection can create significant uncertainty.
A quotation assumption should remain identifiable until the responsible party approves or replaces it.
The system description establishes the starting point for device selection, bus configuration and conductor connections. Provide the actual electrical arrangement rather than a shorthand description that the supplier must interpret.
State the nominal voltage, number of phases, frequency and required circuit conductors.
Examples of clear system descriptions include:
For delta systems, describe the grounding arrangement and any high-leg requirements where applicable. If the single-line diagram contains this information, reference the drawing and revision in the RFQ.
The wiring-system description should also make clear whether a neutral is required. Identify equipment grounding requirements separately.
Include both the required panelboard rating and the proposed main protective-device rating. These values may differ and should not be collapsed into a single “ampere rating” field.
| Electrical input | What to state |
|---|---|
| System voltage | Nominal voltage and system configuration |
| Phase and frequency | Single-phase or three-phase, and Hz |
| Wiring arrangement | Required phase and neutral conductors |
| Panelboard rating | Required current rating of the assembly |
| Main device | Main breaker rating or main lug arrangement |
| Fault-current information | Required assembly short-circuit rating and available fault-current data, where established |
| Special conditions | Service use, unusual system arrangements or project-specific requirements |
Do not use a breaker’s interrupting rating as a substitute for the panelboard’s short-circuit current rating. UL’s application guide explains that the panelboard rating concerns the assembly, including its overcurrent devices and bus structure, and may depend on voltage and specified conditions.
If the required rating has not been established, identify it as an open engineering input. Ask suppliers to state the rating basis of their proposed configuration.
Specify whether the panelboard requires an integral main breaker or a main lug arrangement.
For a main breaker configuration, provide the required poles, current rating and any known trip-unit or accessory requirements. For a main lug configuration, identify the upstream protective device where it affects the proposed arrangement or rating basis.
Also state whether the project requires:
These features can change the interior arrangement and enclosure space. Include them in the base RFQ or list them as separately priced options.
A main breaker requirement does not, by itself, establish that the assembly is suitable for service-equipment use. That intended use needs separate confirmation against the applicable product requirements and markings.
For background, see Main Breaker vs Main Lug vs Service Disconnect.
The incoming arrangement should describe how field conductors will reach and connect to the panelboard.
Provide the following where known:
If conductors have not been selected, ask the supplier to state the proposed terminal capacity and the conductor assumptions used for the enclosure layout.
Top cable entry and top-mounted incoming terminals are separate requirements. A panelboard may need internal routing space between the entry location and the connection point. The RFQ should make both conditions clear.
Detailed terminal suitability and enclosure-space requirements are addressed in Part 2.
The circuit schedule translates the distribution requirement into a device arrangement. It should tell the manufacturer which circuits are required, how they are protected and which positions are reserved.
A load list can support this work, but a list of equipment names and power values may still require engineering decisions before a breaker configuration can be quoted.
For each outgoing circuit, provide enough information to identify the required device or the selection responsibility.
| Schedule field | Information to provide |
|---|---|
| Circuit identification | Circuit number, tag or unique reference |
| Load description | Equipment or area served |
| Connection | Relevant voltage and phase arrangement |
| Breaker requirement | Number of poles and specified current rating |
| Additional protection | Required protective functions or device features |
| Accessories | Shunt trip, auxiliary contacts or other specified items |
| Conductors | Size, material and quantity, where established |
| Remarks | Spare status, special routing or unresolved selection |
Where breaker sizes have already been approved by the project engineer, include them explicitly.
Where the manufacturer is asked to propose devices, provide the necessary load information and identify who approves the selection. A motor, lighting circuit and general-purpose receptacle circuit may require different selection considerations even when their stated load currents are similar.
Also distinguish the number of outgoing circuits from the number of poles or mounting positions. A three-pole device should appear as one coordinated device in the schedule, with its occupied positions clearly identified.
Physical device size depends on the selected panelboard platform. Do not assume that a circuit count alone establishes the required enclosure dimensions.
Separate devices supplied now from provisions intended for later use.
| Requirement | Meaning for the quotation |
|---|---|
| Installed spare breaker | A breaker is included in the supplied assembly but has no assigned connected load |
| Future breaker position | No breaker is supplied; the position is reserved within the approved platform |
| Future provision for a specified device | Space and necessary mounting or connection provisions must be defined for that device |
| General enclosure allowance | Additional physical room is requested, without necessarily providing a usable future circuit position |
“Provide 20% spare capacity” is ambiguous. It could refer to current capacity, installed spare breakers, future mounting positions or enclosure space.
Replace that phrase with explicit quantities and requirements. For example:
Include six installed single-pole spare breakers and reserve six additional single-pole positions for future devices compatible with the approved panelboard configuration.
If future three-pole feeders are expected, state that requirement separately. Their arrangement may affect which positions need to remain available.
Before issuing the RFQ, compare the circuit schedule with the single-line diagram and specification.
Common conflicts include:
If the documents disagree, establish the governing requirement or ask the supplier to identify the discrepancy before finalizing the quotation.
A document-precedence statement helps manage conflicts, but unresolved technical differences should still appear in the quotation review.
The following checklist provides a practical starting point. More information may be needed for a firm quotation or production release.
| RFQ input | Minimum useful submission | If unavailable |
|---|---|---|
| Product and supply scope | Enclosure, interior or complete assembly | Ask for clearly separated scope options |
| Destination and project requirements | Country, specification and required certification | Identify the approval requirement as open |
| Electrical system | Voltage, phase, frequency and wiring arrangement | Resolve before firm device selection |
| Current ratings | Panelboard rating and main-device requirement | Request a proposal with stated assumptions |
| Incoming arrangement | Main breaker or main lug, entry direction | Ask the supplier to identify its proposed arrangement |
| Fault-current requirement | Required assembly rating or project fault data | Keep open and request a stated rating basis |
| Circuit schedule | Device quantities, poles, ratings and spare provisions | Submit a load list and define selection responsibility |
| Conductors | Known material, sizes and quantities | Request proposed terminal capacities |
| Installation | Indoor/outdoor, flush/surface and dimensional constraints | Ask for a proposed enclosure with assumptions |
| Order information | Quantities, delivery location and required timing | Identify estimated quantities and target dates |
| Document control | Drawing numbers, revisions and open-item list | Establish a common quotation document set |
A preliminary quotation should identify which inputs remain provisional and which changes could affect price, dimensions, component selection or delivery.
Once that foundation is clear, the next step is to define breaker requirements, conductor terminations and enclosure interfaces in enough detail to support a consistent configuration.
A breaker schedule that lists only “20 A,” “30 A” or “100 A” leaves important selection decisions unresolved. Devices with the same current rating can differ in voltage suitability, pole configuration, interrupting rating, protective functions, mounting arrangement and accessories.
For a panelboard RFQ, identify the required breaker characteristics and state whether the supplier must use a specific component or propose a suitable selection.
For each breaker type, provide the number of poles, current rating and any specified trip characteristics.
Where relevant, distinguish the breaker frame size from its trip rating or adjustable settings. A request for a “250 A frame” does not necessarily define the current setting required for the circuit.
| Breaker requirement | Information to include |
|---|---|
| Identification | Manufacturer, series and catalog number if fixed |
| Electrical suitability | System voltage, AC or DC application, and poles |
| Current protection | Required rating and specified trip characteristics |
| Adjustable protection | Required functions, setting ranges and responsibility for final settings |
| Additional protection | Ground-fault or arc-fault protection where required |
| Control accessories | Shunt trip, undervoltage release or electrical operation |
| Status indication | Auxiliary contacts, alarm contacts or communications |
| Mechanical provisions | Handle accessories, locking or interlocking requirements |
Accessories should be assigned to individual devices. “Provide auxiliary contacts” is incomplete unless the supplier knows which breakers need them, the contact arrangement and the intended interface.
If a shunt trip is required, include its control voltage and identify whether the quotation must include terminals, internal wiring or an external control interface.
Where final protective settings depend on a coordination study, state who performs that study and when approved settings will be available.
Specify breaker interrupting requirements at the actual application voltage. Keep those requirements separate from the required short-circuit current rating of the complete panelboard.
The RFQ should identify whether the project requires a fully rated arrangement or permits a documented series-rated combination. Where a series rating is proposed, the supplier should identify the applicable upstream and downstream devices and the conditions supporting that arrangement.
A higher interrupting rating on an individual breaker does not automatically increase the rating of the assembled panelboard. The proposed assembly must have an appropriate rating basis for its actual configuration.UL Solutions
Useful RFQ wording is:
State the proposed panelboard short-circuit current rating at the specified system voltage. Identify whether the quotation uses a fully rated or series-rated arrangement and provide the supporting configuration information.
If available fault-current information is still pending, keep it visible as an unresolved project input.
State whether the specified component is mandatory, preferred or open to an approved alternative.
| Procurement instruction | Required supplier response |
|---|---|
| Exact component required | Quote the specified catalog number and disclose availability concerns |
| Preferred manufacturer | Identify the proposed series and catalog numbers |
| Alternatives permitted | Submit the proposed replacement and relevant differences for approval |
| Customer-supplied devices | Confirm the supplied items and review their suitability before assembly |
A replacement must be reviewed for its use in the particular panelboard. Physical fit and matching ampere ratings are insufficient. UL’s breaker guide describes compatibility information for Classified replacement breakers, including the specific panelboards and application limits covered.
Ask suppliers to identify substitutions before purchasing. The review should cover electrical suitability, connection method, accessories, mechanical fit and the assembly’s applicable certification scope.
Terminal requirements influence component selection and usable wiring space. Provide conductor information early enough for the supplier to review both the connections and the enclosure arrangement.
Specify the conductors expected at the incoming terminals and significant outgoing feeders.
Include:
A request for “two conductors per phase” should clarify whether the design needs separate terminal positions or a terminal specifically suitable for multiple conductors.
Terminal markings and instructions determine the permitted conductor material, range and number of conductors. Do not assume that a larger lug, an added adapter or a different conductor preparation method is acceptable without review.
For quotation purposes, request a terminal schedule:
| Connection | Buyer’s conductor requirement | Supplier’s proposed provision |
|---|---|---|
| Incoming phases | Material, size and quantity | Terminal type and stated capacity |
| Incoming neutral | Material, size and quantity | Neutral terminal arrangement |
| Outgoing feeders | Circuit-specific conductor details | Breaker terminals or approved accessories |
| Branch neutrals | Required sizes and quantities | Available individual neutral positions |
| Equipment grounding | Required sizes and quantities | Grounding terminal arrangement |
If conductor details remain provisional, the supplier should state the terminal capacities included in the price.
Define the neutral requirement separately from the phase-bus rating.
The RFQ should state the required neutral current capacity, incoming connection and number of outgoing neutral terminations. Identify any project requirement for an increased neutral rating or particular neutral arrangement.
For circuits that require neutrals, count the required connection positions rather than assuming the circuit count provides a sufficient terminal specification. UL’s panelboard application guide addresses individual branch-circuit neutral terminations; terminal quantity and suitability therefore deserve explicit review.
For panelboards with neutral strips on both sides of the interior, ask the supplier to identify how they are interconnected and how that arrangement is documented.
A neutral bus tie bar can be part of that configuration, but its presence alone does not establish the neutral system’s rating.
Identify the intended installation role and the required relationship between neutral, equipment grounding terminals and the enclosure.
The RFQ should clarify:
The appropriate configuration depends on the electrical system, installation role and applicable requirements. “Provide neutral and ground bars” does not fully describe it.
Where the arrangement is shown on the project single-line diagram or specification, reference that document directly. Any disagreement should be resolved before production approval.
An enclosure specification should describe how the panelboard will be installed, connected and accessed.
Two assemblies with the same current rating and circuit count may need different boxes because their incoming devices, conductor arrangements or installation constraints differ.
State whether the panelboard will be flush-mounted or surface-mounted.
For flush mounting, provide the available wall opening, recess depth, wall construction and required trim overlap. For surface mounting, identify mounting locations and any restrictions imposed by the supporting structure.
Distinguish the dimensions used in the RFQ:
| Dimension | Purpose |
|---|---|
| Backbox dimensions | Define the enclosure body and installation space |
| Overall trim dimensions | Define the visible front coverage |
| Maximum projection | Limits how far the installed assembly extends |
| Door swing envelope | Identifies space needed to open the door |
| Entry coordinates | Locate fixed conduit or cable interfaces |
If the dimensions are maximum limits, label them as such. If they are preliminary, allow the supplier to propose a coordinated size.
Existing replacement installations may require measured interface drawings rather than nominal dimensions.
Specify the required enclosure Type rating and describe the actual environment.
Useful environmental inputs include exposure to rain, windblown dust, washdown, salt, corrosive substances, direct sunlight and the expected ambient temperature range.
Where the project specifies both NEMA Type and IP requirements, list each separately. Avoid treating one designation as an automatic replacement for the other.
Also define relevant construction requirements:
For outdoor equipment, entries, fittings and installation details should be reviewed as part of the specified enclosure arrangement. A suitable empty enclosure does not, by itself, settle every requirement for the completed panelboard.
Provide fixed entry locations before the enclosure layout is finalized.
Large incoming conductors may need space above, below or beside the interior. The supplier needs enough information to review bending, routing and access to the terminals.
The RFQ should also define:
Deadfront openings must coordinate with the selected devices. Future positions need appropriate closures, while access for installation and maintenance must remain practical.
Describe internal wiring space separately from the external working space required at the installation. The manufacturer can review the supplied enclosure; the project team must also coordinate its location and surrounding access.
Before requesting a firm price, ask the supplier to identify any conflict between the proposed components, conductor requirements and enclosure limits. Resolving that conflict during quotation is more manageable than discovering it after the box and interior have been manufactured.
With the electrical and mechanical requirements defined, the RFQ can establish the drawings, documentation and supply boundaries against which competing quotations will be compared.
A panelboard quotation should identify the documents used to define its configuration. Without that reference, the buyer may be unable to determine whether the price includes the latest circuit changes, installation constraints or specification requirements.
Issue a coordinated quotation package and ask each supplier to identify departures from it.
The circuit schedule describes the outgoing circuits and protective devices. The single-line diagram describes how the panelboard connects to the wider electrical system.
Review them together before requesting a firm quotation.
| Requirement | Circuit schedule review | Single-line diagram review |
|---|---|---|
| Panel identification | Correct panel tag and description | Matching system reference |
| Electrical system | Circuit voltages and pole arrangements | Supply voltage, phases and wiring system |
| Incoming arrangement | Main device or main lug requirement | Upstream protection and supply connection |
| Outgoing circuits | Quantities, poles, ratings and spare provisions | Feeders and connected distribution equipment |
| Neutral and grounding | Required circuit connections | System arrangement and bonding requirements |
| Fault-current requirements | Any stated device or assembly ratings | Available fault information and upstream arrangement |
Where information appears in only one document, make its status clear. A supplier should not have to decide whether an omitted feature was intentionally excluded.
If a schedule changes after quotation, identify the revision and request an impact review. Adding a feeder can affect more than the price of one breaker: the device arrangement, terminal provisions, enclosure space and documentation may also change.
Provide installation information that could affect the proposed layout.
For new installations, this may include maximum enclosure dimensions, mounting method, cable-entry direction and available door-opening space.
For replacement projects, submit measured information covering:
Photographs help explain the installation, but important dimensions should appear on a marked drawing or measurement sheet. A photograph alone may conceal depth, alignment and access restrictions.
Ask the supplier to distinguish dimensions that are confirmed from those that remain subject to layout approval.
If field conditions cannot be verified before quotation, identify who will confirm them and whether the price includes a later dimensional revision.
Every issued document should have a clear identifier and revision status.
A simple document register can prevent suppliers from quoting against different information.
| Document | Reference | Revision | Status |
|---|---|---|---|
| Panel schedule | Project-specific reference | Current revision | For quotation |
| Single-line diagram | Project-specific reference | Current revision | For quotation |
| Technical specification | Project-specific reference | Current revision | Applicable sections identified |
| Installation drawing | Project-specific reference | Current revision | Confirmed or preliminary |
| Approved component list | Project-specific reference | Current revision | Mandatory or preferred |
Use quotation-stage documents to establish a price basis. Identify production approval as a separate release step.
A supplier’s quotation may include proposed dimensions or components that still require review. Accepting the commercial offer should not leave uncertainty about whether those proposals have also received technical approval.
A complete panelboard RFQ should state the physical product, engineering documents and verification activities expected within the price.
This is particularly important when comparing an enclosure manufacturer, a panel assembler and a supplier offering a complete manufacturing package.
List the major items included in the supplier’s scope and identify anything supplied by the buyer.
| Scope item | What to clarify |
|---|---|
| Enclosure and trim | Box, door, deadfront, finish, hardware and mounting provisions |
| Interior assembly | Bus structure, insulating supports and breaker mounting system |
| Protective devices | Main and branch breakers, installed spares and accessories |
| Terminations | Incoming lugs, neutral terminals, grounding terminals and connection accessories |
| Internal connections | Bus connections, conductors and accessory wiring within the agreed scope |
| Additional equipment | Metering, surge protection or monitoring devices where specified |
| Identification | Panel tags, circuit directories, component labels and required product markings |
| Packaging | Protection materials, loose-item identification and shipping preparation |
For customer-supplied components, include the exact part numbers, quantities and expected delivery dates. Establish who checks the items on receipt and who handles shortages, damage or unsuitable selections.
Customer supply does not remove the need to review component suitability within the proposed assembly.
If the supplier proposes a different connection accessory or mounting arrangement to accommodate a supplied device, that proposal should enter the technical review before assembly begins.
State which documents must accompany the quotation, which require approval before manufacture and which are required at delivery.
| Stage | Typical deliverables to define |
|---|---|
| Quotation | Configuration summary, proposed components, preliminary dimensions, assumptions and exclusions |
| Approval | General arrangement, breaker schedule, BOM, terminal information and relevant connection drawings |
| Manufacturing release | Coordinated approved documents and a closed or explicitly accepted open-item list |
| Delivery | Final drawings, agreed inspection records, operating information, packing list and applicable certification documents |
The required detail should match the assembly. A panelboard with metering and remotely operated accessories may need additional interface and connection drawings.
For labeling, specify the required language, panel identification and circuit-directory format. Separate customer branding from mandatory product markings.
If the project requires a private-label arrangement, identify the responsible parties and the applicable marking requirements before approving the label artwork.
Define the verification activities included in the quotation and the records expected from them.
Distinguish among:
These activities serve different purposes and may involve different responsibilities.
For a panelboard, the agreed inspection scope may address component identity, assembly condition, connection checks, labeling and document consistency. Accessory-equipped assemblies may also require specified functional checks.
Electrical test procedures and acceptance criteria should follow the applicable product requirements and the actual assembly. Request a defined test scope rather than an unspecified “complete electrical test.”
If witnessed inspection is required, state the notice period, witness arrangements, required records and process for closing findings. Include any effect on shipment release.
Factory acceptance does not replace product certification where required or verification of the installed equipment.
Suppliers can provide useful preliminary pricing while some inputs remain open. The quotation needs to show what has been assumed and what may change when the missing information is supplied.
Ask for a separate assumptions and deviations list rather than allowing important qualifications to remain scattered through the offer.
For each unresolved item, request its effect on the quotation.
| Open item | Supplier response to request |
|---|---|
| Conductor sizes unavailable | Proposed terminal capacity and conductor assumptions |
| Final fault-current requirement pending | Proposed assembly rating basis and conditions for review |
| Enclosure dimensions preliminary | Quoted dimensions and limits of the proposed arrangement |
| Breaker selection awaiting approval | Proposed catalog numbers and substitution status |
| Certification requirement unclear | Included certification scope and any excluded work |
| Installation entries unconfirmed | Factory opening provisions and field-work responsibility |
The quotation should identify which assumptions affect price, delivery, dimensions or product suitability.
Avoid treating “subject to final drawings” as a sufficient explanation. Ask the supplier to name the information that remains provisional.
Alternative configurations can help buyers manage cost and availability, provided the base offer remains clear.
For example, a supplier may offer a preferred breaker configuration and a separately identified alternative with a different delivery period. Each should show the relevant technical differences and approval requirements.
Useful option descriptions include:
Keep installed spare breakers separate from empty future positions. Likewise, distinguish a complete assembly from an offer that excludes selected components or leaves installation work to the buyer.
Use a common comparison sheet before evaluating the total price.
| Comparison point | Questions for each offer |
|---|---|
| Document basis | Does the quotation reference the same drawings and revisions? |
| Electrical configuration | Are the system, current ratings and incoming arrangement aligned? |
| Breaker schedule | Are quantities, poles, ratings, accessories and spares included? |
| Component selection | Are the proposed devices identified and substitutions disclosed? |
| Terminations | Do material, conductor range and quantity match the requirement? |
| Enclosure | Are mounting, dimensions, environmental requirements and entries covered? |
| Rating and certification basis | Is the proposed scope clearly stated for the supplied configuration? |
| Engineering documents | Are the same approval and delivery documents included? |
| Verification | Are inspection, testing, witnessing and records comparable? |
| Commercial scope | Are quantities, packaging, delivery terms and exclusions aligned? |
Where offers differ, ask suppliers to revise them to a common basis or price the differences separately.
A lower initial quotation may leave additional components, engineering work or installation preparation to the buyer. An informed comparison identifies that remaining work and assigns its cost and responsibility.
Before placing the order, assemble the accepted configuration into a clear purchase reference.
That reference should identify:
A firm price can still depend on specified approvals, but those dependencies should be explicit.
The goal is to give procurement, engineering and manufacturing the same understanding of what has been purchased—and what must still be resolved before production release.
Before issuing the RFQ, check that each requirement has a document reference, a stated value or an identified owner for confirmation.
Not every item must be finalized for preliminary pricing. However, suppliers should be able to distinguish fixed requirements from assumptions and proposed options.
| RFQ item | Information to provide |
|---|---|
| Project identification | Project name, panel tag and purchasing reference |
| Destination | Installation country and delivery location |
| Governing requirements | Project specification, applicable standards and required approvals |
| Supply scope | Enclosure, interior, complete assembly or customer-supplied component integration |
| Electrical system | Voltage, phase, frequency and wiring arrangement |
| Current ratings | Required panelboard rating and main-device rating |
| Incoming arrangement | Main breaker or main lug, plus any subfeed or feed-through provisions |
| Short-circuit requirements | Required assembly rating, available fault-current information and any permitted series-rating conditions |
| Intended installation role | Service equipment or downstream distribution, as applicable |
| RFQ item | Information to provide |
|---|---|
| Circuit schedule | Circuit references, loads, breaker poles and ratings |
| Breaker selection | Mandatory catalog numbers or permitted supplier proposals |
| Protective functions | Specified trip characteristics and additional protection |
| Accessories | Device-specific control, indication and communication requirements |
| Spare provisions | Installed spare breakers and future positions listed separately |
| Incoming conductors | Material, sizes and quantity per phase and neutral |
| Outgoing conductors | Known circuit-specific termination requirements |
| Neutral system | Required capacity, terminal quantities and isolation requirements |
| Grounding and bonding | Terminal provisions and the intended bonding arrangement |
| Substitutions | Approval process and required supporting information |
| RFQ item | Information to provide |
|---|---|
| Mounting | Flush or surface mounting |
| Dimensions | Backbox, trim and installation limits |
| Environment | Indoor or outdoor conditions and specified enclosure rating |
| Construction | Material, finish, door and locking requirements |
| Cable entries | Entry direction, fixed coordinates and factory-opening scope |
| Internal access | Terminal access, conductor routing and deadfront requirements |
| Site constraints | Wall depth, nearby obstructions and replacement interfaces |
| RFQ item | Information to provide |
|---|---|
| Document register | Drawing numbers, revisions and quotation status |
| Approval documents | Required layouts, BOM, terminal information and connection drawings |
| Verification | Inspection, testing, witnessing and acceptance-record requirements |
| Certification | Required product marking and supporting documents |
| Quantities | Initial order, panel variants and estimated repeat demand |
| Delivery | Required dates, destination and agreed delivery terms |
| Packaging | Transport protection, loose-item handling and identification |
| Handover | Final drawings, records, instructions and packing list |
| Open items | Assumptions, responsible parties and confirmation milestones |
A practical RFQ package can consist of a completed checklist, the current circuit schedule, a single-line diagram, installation information and the applicable specification sections. A short, coordinated package is easier to quote than a large collection of conflicting documents.
E-abel’s quotation review connects the customer’s requirements with the proposed enclosure, interior, component selection and assembly scope.
The review should establish what can be quoted directly, what requires a supplier proposal and what needs further customer confirmation.
The starting point is the submitted document set.
Relevant inputs include the panel schedule, single-line diagram, installation drawings, preferred components, destination requirements and expected quantities.
The review identifies missing or conflicting information that could affect the proposed configuration. Examples include a different main rating between drawings, an unspecified neutral arrangement or conductor requirements that do not match the proposed terminals.
Where information is incomplete, the quotation can identify the assumptions used for preliminary pricing.
The customer and supplier should establish who selects, supplies and approves each significant part of the assembly.
This includes:
For a three-phase panelboard, the review should coordinate the main device, branch arrangement, neutral connections, grounding provisions and usable conductor space within the proposed enclosure.
Any customer-specific arrangement should be reflected in the approval documents.
The offer should identify the proposed configuration, included work and remaining qualifications.
For an OEM program, buyers should also provide estimated repeat quantities and expected variants. This helps distinguish a one-time project assembly from a product configuration intended for repeat orders.
The quotation can then define the next approval step: confirmation of component selections, submission of coordinated drawings or closure of specific technical questions.
A useful panelboard RFQ makes the required product and remaining decisions visible. It coordinates the circuit schedule, electrical system, breaker requirements, conductor terminations and enclosure interfaces with a defined supply scope.
That clarity helps manufacturers prepare comparable offers and gives buyers a stronger basis for reviewing cost, delivery and technical suitability.
Preparing a panelboard inquiry? Send E-abel your circuit schedule, single-line diagram, installation requirements and expected quantities. Include your required certification scope and preferred components so the quotation can identify a clear configuration basis and any items requiring confirmation.
Yes. Preliminary pricing can be developed from a clear system description, circuit schedule, supply scope and installation requirements.
Ask the supplier to identify assumptions and explain which changes could affect price, dimensions or delivery. Production release requires an appropriately reviewed configuration.
A circuit schedule provides important device information, but usually needs supporting requirements.
System details, incoming arrangements, fault-current requirements, conductors, enclosure conditions and certification scope can materially affect the offer.
Specify it when the project requires a particular manufacturer or series.
If alternatives are acceptable, ask the supplier to identify exact proposed devices and submit differences for review. Approval should address suitability in the proposed panelboard configuration.
Customer-supplied breakers can be considered within an agreed assembly scope.
Provide exact catalog numbers, accessories, quantities and delivery dates. Establish responsibility for receipt inspection, suitability review, shortages and replacements.
An installed spare breaker is included in the delivered product. A spare space is a reserved position without the breaker.
State the quantities and intended future device requirements separately. Additional enclosure space does not necessarily provide a usable future circuit position.
Identify the conductor information as provisional and request the terminal capacities included in the quotation.
Final conductor details may affect terminal selection, accessories and internal routing space, so arrange confirmation before the relevant production decisions are released.
Only if that scope is expressly included and applicable to the supplied configuration.
Clarify the required certification, marking and documents. Component certification and enclosure certification should not be treated as substitutes for the required complete-product certification.
The purchasing agreement should define that milestone.
Commercial acceptance may be followed by drawing submission, component approval and closure of technical items. State what documents and approvals authorize manufacture.
First align the document revisions, component configuration, terminations, enclosure and supply scope.
Then compare included engineering, verification, certification documents, packaging and delivery. Ask for alternatives and exclusions to be priced separately where possible.
The following articles provide supporting guidance for preparing and reviewing a panelboard RFQ:
UL Solutions — Panelboard Application Guide
Guidance on panelboard application, ratings, markings and installation suitability.
UL Solutions — Molded Case Circuit Breaker – Marking and Application Guide
Guidance on breaker markings, application conditions, terminals and replacement compatibility.
UL Standards & Engagement — UL 67: Panelboards
Official standard information for panelboards. Confirm the edition and requirements applicable to the project and certification arrangement.
This checklist supports procurement and engineering coordination. Final selections remain subject to the applicable project requirements, product documentation and approval process.
Juun Wong is Chief Engineer at E-abel. He focuses on electrical panel configuration, component integration and manufacturing documentation, helping OEM buyers turn project requirements into clear specifications.
