Motor Control Center starter coordination defines how an MCC starter combination performs under specified short-circuit conditions. Type 1 and Type 2 differ mainly in the starter's condition after the test.
Choose between them using verified combinations and your required recovery plan.
Coordination Applies to a Starter Combination
A motor starter normally combines switching, overload protection, and short-circuit protection. These functions must work together rather than simply share a current rating.
The contactor switches the motor during normal operation. The overload relay, also called a motor overload relay, responds to excessive sustained motor current.
A short-circuit protective device, commonly shortened to SCPD, handles the specified short-circuit protection duty. The approved combination may use a circuit breaker or suitable fuses.
Type 1 coordination and Type 2 coordination concern the combination's performance. A contactor does not gain either classification just because a catalogue lists its motor power rating.
For European projects, EN IEC 60947-4-1 covers electromechanical contactors and motor starters. Review the manufacturer's applicable combination tables and their stated assessment basis.
Keep this question separate from the MCC enclosure's separation form. Form 4 describes internal boundaries, while starter coordination concerns the performance of selected protective and switching devices.
Six Practical Differences Between Type 1 and Type 2
Type 1 Allows Damage Within Defined Conditions
Under Type 1 coordination, the short-circuit event must not endanger people or the installation. However, the starter may need repair or replacement before further use.
That can include damage to the contactor or overload relay. Therefore, the recovery plan should allow for inspection, suitable spare parts, and qualified maintenance.
Type 1 starter coordination is not the absence of protection. It represents a defined outcome with different expectations for the starter's condition afterwards.
Type 2 Supports Further Use After the Specified Test
Type 2 coordination also requires that the short-circuit conditions create no danger to people or the installation. The starter must remain suitable for further use afterwards.
Limited contact welding may still occur under the defined conditions. The contacts must be readily separable as specified, and the manufacturer provides the required measures.
Therefore, Type 2 starter coordination does not mean every contact remains physically unchanged. Avoid describing it as unconditional zero damage under every possible fault.
Recovery Still Requires a Controlled Decision
Type 2 performance does not authorise immediate re-energising after a real fault. The team must first identify and correct the fault's cause.
Follow the manufacturer's inspection and service instructions. Check the affected circuit rather than assuming the original coordination claim covers unknown damage elsewhere.
For Type 1, the plan must also consider replacement or repair of damaged starter components. Define who approves the circuit's return to service.
The Exact Components Matter
Coordination tables identify combinations of protective devices, contactors, and overload equipment. Their references and settings form part of the selection.
A replacement device with a similar current rating may have different fault behaviour. The same applies when a supplier changes fuse type or breaker characteristics.
Use the listed combination or obtain manufacturer confirmation of an approved alternative. Do not assume that a larger contactor automatically preserves the original coordination.
Voltage and Fault Level Limit the Claim
A combination has stated electrical conditions, including its rated voltage and short-circuit level. Match those conditions to the intended installation.
The prospective fault current at the starter matters. A table for one voltage does not automatically establish the same performance at another voltage.
Review both the supply information and the selected table row. Record the supporting reference so future replacements can follow the same basis.
The Choice Changes Maintenance Planning
Type 1 may suit projects that can accommodate component replacement after a fault. Type 2 may suit projects that prioritise starter serviceability after the specified event.
However, neither option eliminates all downtime. Fault location, cable repair, motor checks, and authorised inspection still affect recovery.
Discuss the required recovery process rather than choosing from the label alone. The best technical specification connects the coordination requirement with actual operating needs.
Question | Type 1 coordination | Type 2 coordination |
|---|---|---|
Danger during specified test | No danger to people or installation | No danger to people or installation |
Starter damage | Repair or replacement may be necessary | Suitable for further use after the test |
Contact welding | Damage may require component work | Limited, readily separable welding may be permitted |
Return after a real fault | Inspection and possible replacement | Inspection and manufacturer-required measures |
Evidence | Applicable tested combination | Applicable tested combination |
Read the Coordination Table Before Ordering
Start with the circuit's actual operating requirements. Select the motor starting arrangement before looking for a matching combination.
Direct starting, reversing, and star-delta arrangements can use different tables. Soft starters also require their relevant manufacturer selection data.
Record the following details for each motor feeder:
Supply voltage and motor operating current.
Starter arrangement and the proposed contactor references.
Exact overload relay reference and required trip class.
Short-circuit protective device reference and relevant settings.
Required coordination type and stated short-circuit level.
Table reference, revision, and any stated restrictions.
Check whether the table covers the installed overload arrangement. Device position and wiring can matter, especially in star-delta circuits.
Ask the supplier to resolve any missing selection before procurement. An incomplete table reference can lead to incompatible substitutions during assembly.
For a mixed motor lineup, do not assume one combination covers every feeder. Each starter needs a suitable selection for its own duty.
Keep Short-Circuit Protection and Overload Settings Distinct
The short-circuit protective device and overload relay address different current conditions. Correct coordination connects their behaviour without making their settings interchangeable.
An overload setting must match the motor and the actual sensing arrangement. Raising that setting to avoid starting trips can weaken motor protection.
Similarly, changing a breaker setting can affect the combination's performance. Check the manufacturer's permitted settings rather than adjusting devices independently.
The overload trip class also needs to suit motor acceleration. However, a suitable trip class alone does not establish Type 2 coordination.
Ask for both pieces of evidence in the design review. Confirm motor protection suitability and confirm the tested starter combination separately.
Tip: Keep the coordination table reference beside the approved feeder bill of materials, so replacements can follow the verified combination.
Compare Recovery Plans Rather Than Labels Alone
Consider two projects with similar motor ratings but different recovery needs. One has trained maintenance staff and readily available spare starter modules.
The other has limited maintenance access and a process that strongly depends on the affected motor. Their preferred coordination choices may differ.
For either project, ask what happens after the protective device clears a fault. Identify who inspects the starter and where replacement equipment comes from.
A useful review considers four questions:
Which components may require attention after the event?
What inspection does the manufacturer require before reuse?
Are matching replacement devices available for the approved combination?
What other faults could keep the process unavailable?
This prevents a narrow focus on contactor survival. A damaged motor cable can still stop production even when the starter remains serviceable.
Avoid promising a fixed recovery time from coordination type alone. The actual fault and the site's response plan determine the work required.
Specify Starter Coordination with Giantele
Provide the motor list and available fault-level information with your enquiry. State the required coordination type for each relevant feeder.
Giantele supplies distribution equipment and offers technical project support. Ask its team to identify proposed starter combinations and the supporting manufacturer tables.
Request a bill of materials that names the protective device, contactor, and overload relay. Include the intended settings and any restrictions affecting substitutions.
For European assemblies, also discuss EN IEC 61439-1 and EN IEC 61439-2 verification. Starter coordination does not replace verification of the complete assembly.
Set a clear approval process for component changes before manufacturing. If a device becomes unavailable, review the alternative combination before accepting it.
At handover, retain the approved tables, settings, drawings, and maintenance instructions. Those records help preserve the intended protection during future repairs.
Conclusion
Type 1 allows repairable starter damage, while Type 2 requires suitability for further use after the specified test.
Both require the correct device combination and a controlled response after an actual fault.
Send Giantele your Motor Control Center feeder requirements and request coordination evidence for the proposed starter combinations.
FAQ
Q: Is Type 2 mandatory for every Motor Control Center?
A: A Motor Control Center does not require Type 2 solely because it controls motors. Select the coordination type from project requirements and verified starter combinations.
Q: Does a Motor Control Center with Form 4 provide Type 2 coordination?
A: A Motor Control Center with Form 4 separation does not automatically provide Type 2 coordination. The two designations address different features and require separate evidence.
Q: Can Type 2 starter coordination permit welded contacts?
A: Type 2 starter coordination can permit limited, readily separable contact welding under defined conditions. Follow the manufacturer's required inspection and separation measures before reuse.
Q: Can I replace the SCPD with any equivalent current rating?
A: The SCPD must match an approved coordination combination. Similar rated current alone does not prove equivalent short-circuit behaviour or preserve the original coordination claim.