DC Surge Protective Devices · RFQ Checklist
DC SPD RFQ Checklist: System, Topology and Surge Ratings
Prepare a DC SPD RFQ from source architecture, topology, surge declarations, installation and exact-model evidence. A useful buyer review connects the project requirement to one exact orderable product and preserves the evidence used for approval.
This checklist organizes inputs for a DC SPD quotation. It does not calculate lightning risk, design a protection system, issue wiring instructions or approve a candidate without exact product and project evidence.
Decision Inputs at a Glance
| Review field | Buyer must define | Evidence to request |
|---|---|---|
| Source | DC source type, voltage architecture and operating limits | Approved system record |
| Topology | Conductor and earth relationships plus protected paths | Single-line and exact SPD diagram |
| Location | Installation point and surge-protection context | Project protection concept |
| Declarations | Required classification and parameter evidence | Exact model row and marking |
| Installation | Enclosure, routing, status, replacement and environment | Installation and maintenance documents |
Freeze the DC System Record First
Identify the DC source, voltage architecture, operating conditions and the equipment being protected. Record whether the application is photovoltaic, battery, conversion equipment or another industrial DC system. Similar nominal voltages can still involve different source behavior and topology.
The RFQ should include the approved system diagram rather than a verbal summary alone. Suppliers can then state their assumptions against the same record. If the design is not fixed, request an engineering clarification before asking for a final product code.
State the Topology and Protected Paths
List the current-carrying conductors, their relationship to earth and the location of the proposed SPD. Ask for the exact manufacturer connection diagram that maps the quoted pole arrangement to this topology. Do not request a pole count as an isolated preference.
Any intentional grounding, isolation or monitoring arrangement belongs in the design record. A generic internet diagram is not acceptable evidence for the project. Where the system relationship is uncertain, keep the quotation technically open.
Define the Installation Location and Protection Context
State where the SPD sits relative to source, incoming boundary, converter, distribution and sensitive equipment. Record upstream and downstream protective devices and any coordinated SPD stages already present. The project designer should define the intended protection concept.
Suppliers should not have to infer exposure from the equipment name. A combiner box, inverter input and DC distribution cabinet can represent different locations and enclosure constraints even within one project.
Request Each Surge Declaration by Name
List the classifications and parameters that require evidence, including the applicable continuous-voltage declaration, protection-level declaration and discharge-current information. Use the project's terminology and ask the supplier to identify the corresponding manufacturer field.
Do not accept a collection of headline values without definitions. Every value should come from the same exact model row and remain attached to its stated test conditions. A family maximum from another variant is not a substitute.
Include Coordination, Indication and Maintenance
Ask for backup-protection requirements, coordination instructions and any upstream or downstream relationships specified by the manufacturer. Separately state whether local status indication, remote signaling or replaceable modules are needed.
For replaceable designs, request matching base and cartridge codes plus the maintenance method. The quotation should show which accessories are included and which are optional. This prevents a technically incomplete low price from appearing equivalent.
Record Physical and Environmental Conditions
Provide enclosure type, available rail space, terminal access, conductor routing limits, ambient conditions and contamination concerns. Ask for dimensions, clearances and installation instructions for the exact assembly.
Keep lead routing and connection details under qualified design control. The RFQ can request evidence without turning a generic article into wiring advice. Any deviation from the manufacturer installation document requires a documented engineering review.
Build an Exact-Model Evidence File
Create one approval record for the proposed DC SPD order code. Put each project requirement beside the supplier document that answers it. Preserve the exact datasheet, drawing, table, instruction or selection output used, including its revision or retrieval date. A category page can establish family context, but it cannot prove an exact rating, terminal arrangement or system combination.
Check that every accepted statement describes the same orderable item. Similar housings can contain different circuits, supplies, terminals, accessories or functions. Do not combine a family maximum from one variant, a diagram from another and an optional feature from a third. Mark unresolved fields explicitly so they remain visible in the commercial review.
Keep Project Inputs Separate From Product Evidence
The project team defines the application: source, load, duty, environment, controls, mechanical limits and required functions. The supplier identifies an exact DC SPD and supports it with exact documents. Neither side should fill a gap by inference from appearance, a shared family name or one matching headline value.
Freeze the application record while quotations are being compared. If the topology, source, load, environment, enclosure or required output changes, issue a revised record and ask each supplier to reconfirm the candidate. Otherwise apparently comparable quotations may be answering different technical requirements.
Common Procurement Errors
Avoid selecting a DC SPD from one headline value while the application context remains incomplete. Do not use a circuit, curve, terminal drawing or performance claim from a neighboring model. A product photograph and a family page can support discovery, but neither is exact technical evidence.
Also avoid assuming that an accessory, communication function, protection role or coordinated result is included unless it appears in the quotation and exact-model documents. A substitute requires the same topology, rating, mounting and evidence review as the original candidate.
How to Compare Supplier Offers
Normalize every DC SPD offer to the same application record. Keep document revisions, stated conditions, included accessories and open questions beside each value. This makes differences in delivered scope visible and prevents a lower-cost but narrower offer from appearing equivalent to a complete solution.
Stop the comparison when a critical application input is unknown, the quoted model is ambiguous, a required claim is supported only by another manufacturer or order code, or the installation falls outside the available evidence. These are engineering gaps, not editorial details.
Control Revisions and Substitutions
Give the approved DC SPD record a revision identifier and keep it with the project file. If the supplier changes the order code, accessory, firmware, drawing or stated operating condition, identify the change before accepting it. A substitution is a new technical proposal even when its price, housing or product-family name looks familiar.
Repeat only the affected checks, but do not waive them. Confirm that the revised candidate still answers the frozen application, that every referenced document belongs to it and that all open exceptions have an owner. This small change-control step prevents a technically reviewed selection from being replaced by an unreviewed commercial equivalent.
Decision Workflow
- Freeze the application and system record before choosing a catalog code.
- Identify the exact function and every interface that requires evidence.
- Request one complete order code with its current datasheet and drawings.
- Map each project requirement to a specific manufacturer statement.
- Record deviations, accessories, document revisions and unresolved questions.
- Repeat the review whenever the application or proposed product changes.
Use this workflow as a procurement and evidence discipline. It does not replace qualified design, installation instructions or the responsible engineer's approval for the DC SPD application.
RFQ Preparation Checklist
A practical dc spd rfq checklist should be concise enough for a supplier to answer and complete enough to prevent silent assumptions. Identify unknown values as questions rather than allowing them to become undocumented selections.
- Source: DC source type, voltage architecture and operating limits.
- Topology: Conductor and earth relationships plus protected paths.
- Location: Installation point and surge-protection context.
- Declarations: Required classification and parameter evidence.
- Installation: Enclosure, routing, status, replacement and environment.
- Exact product code, included accessories and documentation revision
- Quantity, destination, required approvals and commercial scope
Request the exact scope of any classification, compatibility, coordination or performance claim. Record quantity and destination after the technical inputs so commercial terms do not obscure unresolved engineering questions.
Frequently Asked Questions
What is the minimum information for a DC SPD RFQ?
Provide the source, topology, location, required declarations, coordination context and installation conditions.
Should an RFQ specify pole count first?
No. Define the topology and require the supplier to map the exact arrangement to it.
Can I compare suppliers by Imax alone?
No. Compare all required declarations and the system context within the same exact model record.
Related RITOKS Products and Guidance
These links provide product-family context only. A contextual link does not claim interchangeability, compatibility or an approved system combination.
Technical References
These manufacturer sources support only the general engineering concepts described below. Their product ratings, circuit diagrams, approvals and coordination results do not transfer to RITOKS products.
Schneider Electric, Surge Protection Devices: Electrical Installation Guide
Supports the distinction between SPD classification, continuous-voltage, protection-level and discharge-current roles. Schneider values and diagrams do not transfer to RITOKS products.
Phoenix Contact, Surge Protection for Photovoltaic Systems
Supports treating PV DC surge protection as a system-location and topology question. Phoenix Contact ratings and arrangements are not RITOKS evidence.
Request an Exact-Model Review
Send the application requirements, exact-document questions, quantity and destination through the RITOKS contact form. An RFQ requests an exact-model review; this guide does not approve a circuit, installation or automatic substitute.