Motor Starter Panels - Standards

[Charz]

Inorder to reduce the space, we are planning to shift the starters from the MCCs to the near of Motors. So this Starter panel has just starter for one motor. Which Standards would be applied for this starter panel?


We also have an option of providing either from IEC or NEMA starter panels as the project location is in Saudi Arabia.


Which of the IEC / NEMA standards would apply for these standalone motor starter panel?

 

[ptonsparky]

We use Pump Panels for individual motor installations.

 

[paulengr]

MCC is not the only way to control motors.

The Code is still NEC 430 for all motors but NEC describes what is necessary, not how.

Prebuilt combination starters which are essentially an “MCC in a box” and the older method of doing things before MCCs is UL508 where the manufacturer type tests them as a manufactured assembly. The combination part refers to both the disconnect/short circuit means and the contactor. You usually see these where is just one motor or sometimes where there is conduit or a gutter and several drops. When it’s a hazardous location such as fuel storage this is very common in lieu of MCCs because you can buy combination starters in a much larger selection of enclosures. The big disadvantage is all the distribution wiring that this adds compared to the compact space and floor space saving of bus bars.

Custom industrial control panels are UL508A which is essentially a “mini NEC” where a panel builder builds a custom industrial control panel using Listed components. The assembly is UL Listed. Since it is almost totally custom there are almost no limits on design. These are what you see for machine control panels and “PLC” panels. This generally saves even more space and costs but dispenses with isolation between starters. You might have disconnects for mechanical and production purposes but electrically its all or nothing when it comes to servicing. This is fine on one machine with lots of motors but terrible with several isolated systems and one big panel. Think of all the operational problems if you shut down a big chemical plant PLC.

The difference is that UL does not test the final product under UL508A so it avoids the significant expense of third party testing for what are typically one of a kind custom assemblies. A large manufacturer can third party test a combination starter one time then produce thousands so they go the UL508 route.

Even cheaper is CE. Under that Listing the manufacturer self certified like UL508A but they can use any parts they want as long as it is “similar” to a real third party tested part. So nothing is ever third party tested with a CE stamp in reality. That is why CE is not recognized in the US unlike almost all other recognized testing labs. I’m just saying this both as a way of saving money outside of North America as well as a warning since obviously this can drastically inflate your warranty risks.


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[Jraef]

There are no special requirements for motor starters at each individual motor, but you will need to make sure that the SCCR of each unit is sufficient for the Available Fault Current at the point of connection. That generally will mean that each combo starter must have its own circuit breaker or fuses in each one, even though the circuit will have ANOTHER feeder breaker ahead of it in the Distribution Board. So in essence you may end up having duplicate OCPDs on each circuit. the only way around that is if the DB uses the exact same breaker that the Combo Starter is series listed with, or you use a fused switchboard and the fuses are the same as what the combo starter is listed with, AND the non-fused disconnect used at the combo starter has a series listing (not all will). Yopu may find that by the time you get done will all of that, it will cost you more than using an MCC.

Since it is going to Saudi and you have the option for using IEC, you can get IEC MCCs that are more dense than the NEMA / UL versions we use here in North America. You might want to look into that. Most of the major MCC mfrs offer an IEC version if you ask, they just don't sell them for use here because they are not UL845 listed (nor can they be).

 

[don_resqcapt19]

Inorder to reduce the space, we are planning to shift the starters from the MCCs to the near of Motors. So this Starter panel has just starter for one motor. Which Standards would be applied for this starter panel?


We also have an option of providing either from IEC or NEMA starter panels as the project location is in Saudi Arabia.


Which of the IEC / NEMA standards would apply for these standalone motor starter panel?

It would just be a combination starter for a single motor. The combination starter would have to be rated for the enviroment it is located in, and for the voltage and horsepower rating of the motor. No special standards and the use of IEC or NEMA is a design choice, although I prefer NEMA as that equipment will withstand abuse that the IEC equipment will not. If you are always going to "play nice" with the equipment, the IEC is fine.