Best Breaker For The Job

[wreck-it-steve]

Hi,

I have two pumps both rated at 0.75KW and they both need to be on their own breaker... what type breaker would do the job? They both have 1.5mm 3 core flex.

Thanks

 

[PrenticeBoyofDerry]

6Amp

 

[wreck-it-steve]

6Amp

B,C OR D? dont they have a large start up current?

 

[PrenticeBoyofDerry]

You should get away with B types, what purpose do the pumps serve and what does the MI state?

 

[wreck-it-steve]

You should get away with B types, what purpose do the pumps serve and what does the MI state?

They are sewage pumps and the install manual says:

0.75kw moter rated MCB @ 10A

 

[PrenticeBoyofDerry]

Follow the MI then

 

[mfarrow]

If the manufacturers are saying 10A then 10A it is, although you could probably get away with a C6 breaker as I'm sure the only reason it's that high is for startup current.

 

[wreck-it-steve]

If the manufacturers are saying 10A then 10A it is, although you could probably get away with a C6 breaker as I'm sure the only reason it's that high is for startup current.

The pump manufacturers are not saying 10a, it was a 10 year old document from when the tank etc was installed. Im sure the pumps are about 5.5A each so C6 would be OK and allow room for the startup current?

 

[PrenticeBoyofDerry]

The pump manufacturers are not saying 10a,

the install manual says:

0.75kw moter rated MCB @ 10A

 

[xr4x4]

Get a c6 type c then.

 

[wreck-it-steve]

The pump manufacturers are not saying 10a,

the install manual says:

0.75kw moter rated MCB @ 10A

By manual i mean a 10 year old document from when the tank etc was installed. The pump specs have come off the pumps over time.

 

[bernardgreen]

We have a sewage pump here and I can assure you that high and prolonged start up currents have to be allowed for. That is especially so for the motor that drives the macerator which may have to start against a heavy mechanical load.

 

[securespark]

Lots of poo is a heavy mechanical load?

 

[wreck-it-steve]

We have a sewage pump here and I can assure you that high and prolonged start up currents have to be allowed for. That is especially so for the motor that drives the macerator which may have to start against a heavy mechanical load.

So stick with the B10 or go for a C6?

 

[mfarrow]

C6 will be better for start-up current, and would better protect the pump under overload conditions.