Maximum Starts per Hour

[georgedvf]

Hello!

Is there a average standard of Maximum Starts per Hour recommended for certain range of size and types of compressors?

I'd be thankful if you could help me getting some info about it.

For example: a 10HP reciprocating compressor has Maximum Starts per Hour = 8 (not a real value, just an example).

Thanks in advanced!

[cool runings]

Hello!

Is there a average standard of Maximum Starts per Hour recommended for certain range of size and types of compressors?

I'd be thankful if you could help me getting some info about it.

For example: a 10HP reciprocating compressor has Maximum Starts per Hour = 8 (not a real value, just an example).

Thanks in advanced!

6 starts per hour is what most manufacturers work to..

coolrunnings

.

[chilliwilly]

Yes there is a guidance note from each motor manufacturer that will give guidance on starting, stopping, and plugin reversal. Usually in the case of fridge and aircon, even on the older systems before soft starts and VVF and DC drives. They used traditional winding configuration, and voltage limit control, transformers, external resistors, and mercury valve rectifiers were quite common with industrial applications. And sometimes the methods were chosen and implemented by the designer/installer, and not always by the manufacturer. And sometimes introducing new starting methods never seen or used before in traditional starting methods.

When you look at the same problems with compressors, they wil give you the bare minimum starts to edge their bets, due to the expected high starting torque load. This value will differ somewhat with the actual motor characterisitc specification, given by a different manufacturer. For the same size motor that is a stand alone motor that is ready to be coupled to a load.

You can find and follow a single guide that will be handy to keep in your pocket. Or just go with a particular manufacturers guidance for their products.

I know a 500 HP 415v 6 pole squirrel cage motor using a traditional star/wye delta, is specified to only have up to seven starts and plugin reverses in an hour. This was specified by Brook Crompton for the coupled load application it was designed for. But they give several other specs for different loads, utilizing the full torque load capabillity of the motor.

Jaque Hay gave totally different specs for the same size motor, as did Siemens. A lot of the time the specs were ignored, and sometimes the motors burnt out. And sometimes they run for years with no problems. In the case of them being rewound, it depended on which firm did the rewind. And whether it was an emergency rewind, or a non essential one.

[georgedvf]

Thanks, so there's no General considerations??? Do you have some links to where I can find this info of BITZER compressors? I've been looking and can't find it.

[cool runings]

Thanks, so there's no General considerations??? Do you have some links to where I can find this info of BITZER compressors? I've been looking and can't find it.

http://www.bitzer.de/eng/products/docu/doc_ov/2

technical information

Bitzer say no more than 8 starts an hour.

coolrunnings

.

[Aik]

Bitzer say no more than 8 starts an hour.

Exactly.
Check this
http://www.bitzer.de/eng/productservice/p4d/KT-100

[martinw58]

6 starts per hour

[georgedvf]

Thanks to all! The Bitzer link helped a lot!

Regards.