Table Saw trips RCBO

[Bedders]

I have a ring cct (2.5mm ) in my cabin which is protected by a 20amp RCBO. This has been in existence for over 3 years with no issues. I recently bought a table saw and when turned on, on its own all is OK. However the other day I had a heater and a dust extractor on, then turned on the table saw, the RCBO immediately tripped. It only trips when other appliances are on and you turn on the table saw. My question, is there a way to dampen the start up of the tablesaw motor or would I have to upgrade the RCBO to 32amp. The table saw is a Dewalt with a 2000watt motor. It is a bit aggressive on star up. Ideally is there something it can be plugged into to reduce the initial surge it creates.

 

[plugsandsparks]

Try starting saw first, dust extractor second and heater last. If the heater is a 2KW fan heater you will be close to the limit without the extra load of starting the motor anyway. Saw , hopefully, when its running will take a much lower current than what its rated at.

 

[Bob Geldoff1234]

What ever you do,do not change the RCBO to a 32amp.The 20amp is there to protect the cable.You are basically overloading the circuit.As Plugsandsparks says use the saw first or unplug other items while using the saw.

 

[timhoward]

The simplest solution is probably turn the heater off while sawing!

As the others have said, you are likely pushing the circuit design as heating generally consumes a lot of power. I'd expect if you look at the ratings on the extractor and the heater and add up the power in watts, and then add 2000 for the saw you'll be at over 4600 watts which in simple terms is the peak limit of a 20A circuit, and it shouldn't be running with even this load for long periods.

If you will want these three things on together regularly then you need someone to look at the supply to the cabin (which is the limiting factor) and see what can be done. There may well be simple solutions but a lot more info is needed to say something is safe.

When you say ring circuit, is it actually a complete loop or a more common daisy-chained (radial) socket circuit?

 

[Bedders]

The simplest solution is probably turn the heater off while sawing!

As the others have said, you are likely pushing the circuit design as heating generally consumes a lot of power. I'd expect if you look at the ratings on the extractor and the heater and add up the power in watts, and then add 2000 for the saw you'll be at over 4600 watts which in simple terms is the peak limit of a 20A circuit, and it shouldn't be running with even this load for long periods.

If you will want these three things on together regularly then you need someone to look at the supply to the cabin (which is the limiting factor) and see what can be done. There may well be simple solutions but a lot more info is needed to say something is safe.

When you say ring circuit, is it actually a complete loop or a more common daisy-chained (radial) socket circuit?

It's a sub board in a cabin fed by a 10mm swa 3 core, at about 20meters from the main board feed. The cct is a true ring cct wired with 2.5mm cable. Not a radial.

 

[mainline]

What ever you do,do not change the RCBO to a 32amp.The 20amp is there to protect the cable.You are basically overloading the circuit.As Plugsandsparks says use the saw first or unplug other items while using the saw.

32amp is the normal rating for a 2.5mm ring final ?

 

[mainline]

It's a sub board in a cabin fed by a 10mm swa 3 core, at about 20meters from the main board feed. The cct is a true ring cct wired with 2.5mm cable. Not a radial.

Just up the 20amp to a 32

 

[Bedders]

32amp is the normal rating for a 2.5mm ring final ?

Yes it is, but at the time of install they had a 20amp spare and we did not have anything heavy in there. So I could easily upgrade the RCBO.

 

[Bedders]

Just up the 20amp to a 32

Think that's the best solution. Thanks all for your input.

 

[pc1966]

Is it a B-curve or C-curve? If it is just the peak start-up that is tripping it then changing to 20A C has less concern about the specifics of the cable feeding it.