MV Switchgear Pre-Purchase Checklist: 10 Critical Points

1. Confirm the Design Basis and Standard References

Before signing any medium voltage panel order, verify that the technical proposal matches the project requirements exactly. The design basis statement should list the applicable standards, such as IEC, IEEE, or national regulations. If the supplier references an older standard revision, check whether the local utility or authority requires the latest edition.

A common mistake is accepting a generic design without checking the specific standard clauses. For example, if the project requires high-temperature operation, the design basis must state the ambient temperature limit and the derating method. If the proposal only mentions “standard conditions,” ask for clarification.

Red flags:

• No specific standard numbers listed in the proposal.
• Vague language like “in accordance with applicable standards” without naming the standard.
• Missing ambient temperature or altitude specifications.
• Design basis copied from a previous project without project-specific details.

2. Verify Protection Coordination and Fault Current Calculations

The medium voltage panel must be sized for the actual fault current and the required short-circuit duty. Review the short-circuit calculation report provided by the supplier. It should show the maximum short-circuit current, the impedance used, and the coordination with upstream and downstream devices.

Check that the breakers, fuses, and protective relays are coordinated to clear faults within the specified time. If the relay settings are not final, request a preliminary coordination study. An uncoordinated system can trip the wrong device, causing unnecessary outages or equipment damage.

Red flags:

• No short-circuit calculation report attached to the proposal.
• Breaker ratings significantly lower than the calculated fault current.
• Missing relay setting schedules or coordination studies.
• Supplier refuses to provide the calculation assumptions.

3. Review the Equipment Scope and Bill of Materials

The bill of materials (BOM) must list every component in the medium voltage panel. Include breakers, fuses, meters, relays, busbars, insulators, and control units. Verify that the BOM matches the single-line diagram. A missing component in the BOM can lead to change orders or site delays.

Pay attention to the ratings of each device. For example, if the BOM lists a 1200 A breaker but the one-line diagram shows a 1600 A circuit, there is a mismatch. Also check the voltage rating. A 12 kV breaker in a 24 kV system is a serious error.

Red flags:

• BOM items do not match the one-line diagram.
• Generic descriptions like “control unit” without model numbers or specifications.
• Missing accessory items such as earthing bars, cable glands, or cable trays.
• Supplier uses “or equivalent” language without defining the equivalence criteria.

4. Confirm Factory Acceptance Tests and Witness Test Protocols

Factory acceptance tests (FAT) verify that the medium voltage panel works as specified. The contract should define which tests are mandatory and which are optional. Common tests include insulation resistance, dielectric withstand, short-circuit withstand, and relay trip tests.

Decide whether your team will witness the tests at the factory or rely on test reports. If you witness tests, state the number of personnel allowed, the travel expenses, and the test report format. If you do not witness, require signed test reports with witness signatures from the supplier.

Red flags:

• No FAT protocol in the contract.
• Supplier excludes critical tests from the scope.
• Test reports are not signed by an authorized representative.
• No provision for retesting after failures.

5. Check Documentation and Manual Requirements

The medium voltage panel must arrive with complete documentation. This includes as-built drawings, operation and maintenance manuals, test reports, and spare parts lists. Without these documents, maintenance becomes difficult, and future modifications are risky.

Require that the manuals are in the project language. If the project is in a non-English speaking country, specify that translations are included in the price. A missing translation can delay commissioning by weeks.

Red flags:

• Manuals are only available in English or the supplier’s native language.
• No as-built drawing package included in the price.
• Test reports are not part of the deliverables.
• Supplier offers to sell documentation separately.

6. Define Spare Parts and Training Requirements

Plan for long-term operation. The contract should include a minimum quantity of spare parts, such as fuses, relays, and control units. Specify the storage conditions for spare parts. If the spares are sensitive to humidity or temperature, state the required packaging.

Training is often overlooked. If your maintenance team has limited experience with the specific panel, require a training program. Define the duration, location, and number of trainees. A two-day training session may not be enough for complex relay configurations.

Red flags:

• No spare parts list in the contract.
• Training is optional or not included in the price.
• Supplier does not provide training materials or certificates.
• Spare parts have a long lead time but are not ordered in advance.

7. Verify Contractual Terms and Acceptance Criteria

The commercial contract must match the technical scope. Check the price breakdown. A lump-sum price without a breakdown makes change orders difficult to manage. Require a detailed price schedule showing equipment, testing, documentation, and shipping.

Define the acceptance criteria. What happens if the panel arrives with a defect? State the inspection period at the site. If the defect is found, the supplier must correct it within a defined timeframe. Include penalty clauses for late delivery and non-conforming equipment.

Red flags:

• Price is a lump sum without a breakdown.
• No acceptance period defined in the contract.
• Penalty clauses are vague or missing.
• Supplier refuses to sign the acceptance certificate.

8. Review Delivery, Packaging, and Installation Support

The medium voltage panel must be delivered in a condition that protects it from damage during transit. Check the packaging specifications. Heavy-duty wooden crates with shock indicators are typical. If the panel contains sensitive electronics, require climate-controlled packaging.

Confirm the delivery schedule. Ask for a milestone plan showing when manufacturing, testing, and shipping will occur. If the delivery is late, define the consequences. Also check who handles installation support. Some suppliers provide installation supervision, others do not.

Red flags:

• No packaging specifications in the contract.
• Delivery schedule is vague or missing.
• No installation support defined.
• Supplier does not provide a milestone plan.

9. Confirm Quality Control and Inspection Points

The supplier must perform quality control at defined points. These points include incoming material inspection, in-process inspection, and final inspection. Request a quality control plan. It should list the inspection points, the inspection criteria, and the responsible personnel.

If you have a quality assurance engineer, schedule inspections at key points. For example, inspect the busbar fabrication before assembly. Inspect the relay configuration before FAT. These inspections catch errors early when correction is cheaper.

Red flags:

• No quality control plan provided.
• Supplier does not allow inspections.
• Inspection criteria are not defined.
• No responsible quality personnel listed.

10. Check Warranty, Liability, and Dispute Resolution

The warranty period must be clearly defined. A standard warranty is often one year from delivery. Check what is covered. Does it cover parts, labor, or both? If a breaker fails within the warranty period, the supplier must replace it without charge.

Define the liability for defects. If the panel causes damage to other equipment, who is responsible? State the limitation of liability. Also define the dispute resolution process. Arbitration or litigation should be specified with the governing law.

Red flags:

• Warranty is only for parts, not labor.
• No liability limit defined.
• Governing law is unclear or unfavorable.
• Supplier refuses to sign the warranty certificate.

Summary Table: Quick Reference Checklist

Item	Verification Point	Red Flag
Design Basis	Standard references and ambient conditions match project needs	Vague standard references
Protection Coordination	Fault current calculations and relay settings are included	Missing coordination study
Bill of Materials	BOM matches one-line diagram and ratings are correct	Missing or mismatched items
Factory Tests	Test protocol and witness rights are defined in contract	No FAT protocol
Documentation	As-built drawings and manuals are included in price	Documentation sold separately
Spare Parts	Minimum quantity and storage conditions are specified	No spare parts list
Contract Terms	Acceptance criteria and penalty clauses are clear	Vague acceptance terms
Delivery Support	Packaging and installation support are defined	No installation support

Final Verification Steps

Before signing, perform a final review of all documents. Compare the technical proposal, the bill of materials, and the contract scope. Ensure that every item in the checklist is addressed. If any item is missing, request clarification in writing. Do not rely on verbal promises.

The goal is to reduce risk. A well-verified medium voltage panel order avoids change orders, delays, and operational issues. Use this checklist as a baseline. Adjust it based on the project complexity and local regulations. A thorough pre-purchase review protects the investment and ensures a smooth commissioning process.