Pressure washer trips fuse?

[Andehh]

I bought a Nilfisk E140 pressure washer, first time I used it tripped the garage and main house fuse box.

Resetting them, and it tripped it again.

I sent it back figuring electrical fault but the replacement doe exactly the same.

The main & garage fun boxes are set at 16amps,and they garage has nothing of high power usage in it. An old hi-fi and electrical garage door.

Anyone ever had similar issues? Could increasing the fuse size (via electrican) be an option?

For what it worth, it's a new build house, fuse box installed by qualified electrician a year ago a part of new kitchen installation.

Thanks

[Magic919]

I have a different make and only had problems on an extension lead. Some people seem to have trouble when they have an RCD.

[motco]

Are you sure that it is tripping the over-current device (aka fuse), or the RCD? It is very credible that it will trip an RCD because even the slightest moisture where it shouldn't be will cause a leak to earth. My house has an RCD on certain circuits and when I cleaned a fixed kitchen appliance once the RCD would trip for a couple of weeks until the water in the switch dried out.

[CorradoTDI]

Maybe something wrong with the socket you're plugged into?

[LotusMartin]

I had the same problem with my E140, I made up an extension out of some yellow arctic cable (2.5mm core if I remember correctly) and it works a treat now.

[Andehh]

No issues when plugging into the 32amp kitchen ring circuit.

Yes, it's not tripping the 13amp plug fuse, but it is tripping both the garage and main house 16amp RCDs. Both get flipped when I use the garage circuit.

[eliot]

RCD's dont have a current rating unless they are combined rcd and mcb, known as rcbo.

If the thing that is tripping has a little test button it's either a rcd or rcbo.

If it doesn't have a test button - it's an MCB (or fancy fuse)

If it's tripping a 16a MCB then there is something badly wrong with it and it needs looking at.

If it's tripping the rcd or rcbo then as mentioned even the slightest bit of moisture in a plug or something will trip it.

[KAgantua]

Coult there be significant voltage drop if:

- Pressure washer is powerful (eg 2000w)
- Mains cable for PW is long, then You are running a long extension reel off it, plugged into the shed/ garage, which is a long way from the house, and a long cable through house back to box.

Happens at my house.
Plugging it directly into house or extension reel in house is fine, but in the shed - anything powerful trips.

j

[Piersman2]

Try changing the rcd out for a type C.

Standard (Type B)have a hair trigger trip, type C allows a slight delay before it trips to allow for high current start up electric motors.

I only found this out after years of my compressor tripping the garage fuse about 50% of the time. when I bought a scissor jack, it would trip every time and I mentioned it to an electrician mate. He stright away said change to a type C.

I changed my 16A type B, to a 20A Type C. Never tripped with either compressor or scissor jack since.

http://www.screwfix.com/p/havells-20a-single-pole-...

[eliot]

Piersman2 said:

Try changing the rcd out for a type C.

Standard (Type B)have a hair trigger trip, type C allows a slight delay before it trips to allow for high current start up electric motors.

I only found this out after years of my compressor tripping the garage fuse about 50% of the time. when I bought a scissor jack, it would trip every time and I mentioned it to an electrician mate. He stright away said change to a type C.

I changed my 16A type B, to a 20A Type C. Never tripped with either compressor or scissor jack since.

http://www.screwfix.com/p/havells-20a-single-pole-...

And you are still mixing up RCD and MCB!
And changing from a 16 to 20 amp MCB(a fuse) is potentially dangerous if the cable isn't up to scratch.

You should of just swapped the 16a type b for a type c

Edited by eliot on Monday 22 August 08:37

[motco]

A pressure washer is an electric machine full of water. It's begging to be allowed to trip an RCD! I'd put odds on the problem being an earth leak rather than over-current.

[Royce44]

Andehh said:

No issues when plugging into the 32amp kitchen ring circuit.

Yes, it's not tripping the 13amp plug fuse, but it is tripping both the garage and main house 16amp RCDs. Both get flipped when I use the garage circuit.

something wrong with your garage sockets then if im teading that right. also you shouldnt have the same rating rcd for garage and house, if garage is 30ma then house shpuld be like a 100ma time delay

[Smiler.]

eliot said:

Piersman2 said:

Try changing the rcd out for a type C.

Standard (Type B)have a hair trigger trip, type C allows a slight delay before it trips to allow for high current start up electric motors.

I only found this out after years of my compressor tripping the garage fuse about 50% of the time. when I bought a scissor jack, it would trip every time and I mentioned it to an electrician mate. He stright away said change to a type C.

I changed my 16A type B, to a 20A Type C. Never tripped with either compressor or scissor jack since.

http://www.screwfix.com/p/havells-20a-single-pole-...

And you are still mixing up RCD and MCB!
And changing from a 16 to 20 amp MCB(a fuse) is potentially dangerous if the cable isn't up to scratch.

You should of just swapped the 16a type b for a type c

Edited by eliot on Monday 22 August 08:37

Even this is not always plain sailing.

Type C has a lower permissible circuit earth-loop impedance due to the different tripping characteristics & are selected to suit the circuit by design. This effectively halves the permitted circuit length from Type B to C & again from Type C to D. Of course, the installed loop impedance by design will depend upon the cable type, conductor CSA & circuit configuration.

Royce44 said:

Andehh said:

No issues when plugging into the 32amp kitchen ring circuit.

Yes, it's not tripping the 13amp plug fuse, but it is tripping both the garage and main house 16amp RCDs. Both get flipped when I use the garage circuit.

something wrong with your garage sockets then if im teading that right. also you shouldnt have the same rating rcd for garage and house, if garage is 30ma then house shpuld be like a 100ma time delay

It doesn't quite work like that.

The tripping time of an MCB is far less than a 1363 fuse - for a given current. If it is however an earth leakage issue (which I suspect it is) & there is an RCBO (MCB with integral RCD trip) protecting the circuit, then the fault current will be too low for the fuse.

Also, cascading RCD trip currents almost never works due to the sensitivity. Same with MCB's unless there is a big gap between the nominal trip current in the upstream & downstream & even then, not all MCBs will.

Typical arrangement would be 40A in main consumer unit, 16A max downstream. 30mA on the feed to garage, no RCD on circuits feeding internal in garage, 30mA for sockets feeding outside stuff (could be a plug-in module).

motco said:

A pressure washer is an electric machine full of water. It's begging to be allowed to trip an RCD! I'd put odds on the problem being an earth leak rather than over-current.

This.

OP, can you clarify that all the breakers in the house have RCD trips.

Same question for the garage.


If the one feeding the garage does & the one feeding the kitchen doesn't, it would suggest an earth-leak or neutral-earth fault.

Not sure how the latter might come into play but could be something amiss with the garage install.

Also, have you got a plug-in RCD trip adaptor?

[Andehh]

Yes, both ''fuse boxes' have RCD. The one in the kitchen is a metal box, brand new, to comply with the latest Regs.

One in the garage is a plastic one, with a master red 'cut off' and two RCD breakers. One for the lights, one for the 2 x double sockets and elec garage door.

Pressure washer is rated at 2100w, it replaced my old Vax one which is rated at 2000w.


Both Nilfisk pressure washers were refurb'd but bone dry when i tried them, neither managed to get water through before tripping the RCDs.

[motco]

Andehh said:

Yes, both ''fuse boxes' have RCD. The one in the kitchen is a metal box, brand new, to comply with the latest Regs.

One in the garage is a plastic one, with a master red 'cut off' and two RCD breakers. One for the lights, one for the 2 x double sockets and elec garage door.

Pressure washer is rated at 2100w, it replaced my old Vax one which is rated at 2000w.


Both Nilfisk pressure washers were refurb'd but bone dry when i tried them, neither managed to get water through before tripping the RCDs.

The obvious conclusion is that your 32A kitchen circuit that does not trip is not on an RCD. Is it the same circuit as used by your fridge/freezer?

[Andehh]

motco said:

The obvious conclusion is that your 32A kitchen circuit that does not trip is not on an RCD. Is it the same circuit as used by your fridge/freezer?

Yes it is! Though I do think it is on a RCD, looks the same as the garage except the garage is 16amps & the other is 32amps.

[Jonesy23]

It might be earth leakage (though not necessarily due to a fault) or it could just be a high inrush current causing the trip.

If a higher capacity RCD of the same type and trip level (both 30mA?) is ok then I would suspect the instantaneous current from inrush is underlying issue.

[Andehh]

Jonesy23 said:

It might be earth leakage (though not necessarily due to a fault) or it could just be a high inrush current causing the trip.

If a higher capacity RCD of the same type and trip level (both 30mA?) is ok then I would suspect the instantaneous current from inrush is underlying issue.

Neighbour's father who was an electrician recons it is the high rush of current on initial start up and the RCD may just be particularly sensitive to it.

Can I risk increasing the garage RCD to 20amps, instead of 16amps, to compensate for this?

[Jonesy23]

Andehh said:

Neighbour's father who was an electrician recons it is the high rush of current on initial start up and the RCD may just be particularly sensitive to it.

Can I risk increasing the garage RCD to 20amps, instead of 16amps, to compensate for this?

As has been mentioned earlier the solution is probably to change to a Type C breaker which will better tolerate the instantaneous current, but keep it a 16A one.

[eliot]

Andehh said:

Can I risk increasing the garage RCD to 20amps, instead of 16amps, to compensate for this?

And RCD is not an MCB - you cant increase it to '20 amps' - (unless it's an RCBO which is a combined RCD and MCB)

If you cant identity what parts you are working with and the correct terminology, then I suggest you get someone in who knows what they are talking about.