Zanussi ZWC 1300W

[blackrose]

My washing machine stopped mid-cycle and is now completely unresponsive - no lights. I've switched it off and back on again on the machine and at the mains socket but nothing.

 

I was running it from the mains at the time and shore power is working fine. I've tried restarting it with the inverter but it doesn't seem to make any difference. 

 

About 15 years ago the same thing happened with the same machine but I didn't realise and opened the door with a drum full of water, flooding the bathroom - so I don't want to do that again.

 

Does anyone have any tips on how to reset it? I will check the fuse in the plug...

[cuthound]

Most likely cause is the plug top fuse having blown. They do occasionally fail with age 

 

When I working in the critical power industry all fuses were routinely changed every 5 years to avoid fuses failing unexpectedly.

Edited September 12 by cuthound
spillung

[blackrose]

20 minutes ago, cuthound said:

Most likely cause is the plug top fuse having blown. They do occasionally fail with age 

 

When I working in the critical power industry all fuses were routinely changed every 5 years to avoid fuses failing unexpectedly.

 

Yes, sorry, it was the 5A fuse.  I changed it to a 13A fuse as that's all I had - is that ok?

[nicknorman]

The manual specifies a 13A fuse. 5 A is only about 1200 watts. The washer uses about 1600 watts when the heater is on. This is why the fuse blew!

Edited September 12 by nicknorman

[blackrose]

23 minutes ago, nicknorman said:

The manual specifies a 13A fuse. 5 A is only about 1200 watts. The washer uses about 1600 watts when the heater is on. This is why the fuse blew!

 

Ah, well it had been going ok with a 5A fuse for the last 15 years or so. I guess it eventually gave up.

[nicknorman]

4 minutes ago, blackrose said:

 

Ah, well it had been going ok with a 5A fuse for the last 15 years or so. I guess it eventually gave up.

Yes a 5A fuse can take 5A indefinitely, and so it won't blow on a fairly short term modest overload for several minutes or even hours. But it will get very hot and eventually fatigue fail.

[jim mitchell]

5 hours ago, nicknorman said:

The manual specifies a 13A fuse. 5 A is only about 1200 watts. The washer uses about 1600 watts when the heater is on. This is why the fuse blew!

May be worth a mention Nick, but I believe the present  BS gives 3 and 13A fuse sizes as standard for 3 pin  mains plugs, but 1, 2, 3, 5, 7 10 are all fairly easy to find as well as 13 A.  I have noticed many appliances being supplied with 13A fuses which is way higher than needed even if inrush currents are considered. Mainly i suspect as it offers a simple solution to suppliers and (?misleadingly) peace of mind to those who do not consider all aspects.

  Oversize fuses will not necessarily blow but neither do they really protect against faults in the equipment and potential fires as a result.

The occasional blown fuse (and minor inconvenience) from being slightly small in Amps imho is better than being largely overrated,  Personally I would opt for a 10A or maybe even just a 7A (= 1680 watts at a true 240v) for this machine / location.

People rightly worry about DC fuse ratings to protect cables etc but i believe do not apply the same degree of thought to AC power / fuses.

[nicknorman]

2 minutes ago, jim mitchell said:

May be worth a mention Nick, but I believe the present  BS gives 3 and 13A fuse sizes as standard for 3 pin  mains plugs, but 1, 2, 3, 5, 7 10 are all fairly easy to find as well as 13 A.  I have noticed many appliances being supplied with 13A fuses which is way higher than needed even if inrush currents are considered. Mainly i suspect as it offers a simple solution to suppliers and (?misleadingly) peace of mind to those who do not consider all aspects.

  Oversize fuses will not necessarily blow but neither do they really protect against faults in the equipment and potential fires as a result.

The occasional blown fuse (and minor inconvenience) from being slightly small in Amps imho is better than being largely overrated,  Personally I would opt for a 10A or maybe even just a 7A (= 1680 watts at a true 240v) for this machine / location.

People rightly worry about DC fuse ratings to protect cables etc but i believe do not apply the same degree of thought to AC power / fuses.

Sorry but I rather disagree! The old adage is correct in that the fuse is to protect the cable not stuff within the appliance. Especially an appliance with a very variable power consumption. In the case of the Zanussi the heating element is around 1300 watts and the other stuff is much less. So for example if the motor or a valve or even the controller had a fault, it could easily generate enough heat to cause a fire without consuming as much current as the 1300w heating element. Same applies to a dishwasher.

Obviously there is nothing wrong with fitting a smaller fuse but I think the enhancement in safety would be as close to zero as to not matter. 

[Alan de Enfield]

3 minutes ago, jim mitchell said:

I would opt for a 10A or maybe even just a 7A (= 1680 watts at a true 240v)

 

But for many years now the UK Main has been 230 volts (since closer alignment with Europe in 2009) but can be as low as 220v

 

7A at 230v = 1610 watts which I would consider to be borderline for a1600w machine

[blackrose]

46 minutes ago, nicknorman said:

Obviously there is nothing wrong with fitting a smaller fuse but I think the enhancement in safety would be as close to zero as to not matter. 

 

Out of interest why don't we size AC fuses based on the current draw of the appliance as we do for DC systems? I know the fuse is there to protect the cables but the cables themselves are should be adequately sized to reduce voltage drop based on return length and current draw and the fuse is also rated based on the current draw of the DC appliance. So why is it more critical to get that right than it seems to be for AC appliances?

Edited September 12 by blackrose

[jim mitchell]

38 minutes ago, Alan de Enfield said:

 

But for many years now the UK Main has been 230 volts (since closer alignment with Europe in 2009) but can be as low as 220v

 

7A at 230v = 1610 watts which I would consider to be borderline for a1600w machine

Very true Alan , but it can be as high as 253v legally (the EU 230 +10%) i believe, in my house, which is close to a sub station its normally 249v.

My reason in mentioning it at all is because i strongly suspect few people ever check a cable size or consider it on AC units and some equipment i have found on sale is fitted with a standard 13amp fuse but a light flex of only  0.75mm2 which is not rated for it and yes it was CE marked !!!  - plus for whatever reason (feasibly lack of knowledge as to the result) i have seen many cases of people simply fitting a 13A fuse because they have one to hand when a 3A lamp fuse has blown.

 

 

[hider]

But of course fuses melt at more than the rated current marked on them, by as much as double. In the event of a short circuit, the plug fuse will "blow" no matter which rating it is before the flex which it is protecting melts.

It is for the steady overloads that the rating becomes important, like 20 to 30 % overloads where a thinner flex may well get warm before the fuse finally melts, after quite while, hours sometimes. 

[nicknorman]

1 hour ago, blackrose said:

 

Out of interest why don't we size AC fuses based on the current draw of the appliance as we do for DC systems? I know the fuse is there to protect the cables but the cables themselves are should be adequately sized to reduce voltage drop based on return length and current draw and the fuse is also rated based on the current draw of the DC appliance. So why is it more critical to get that right than it seems to be for AC appliances?

 In narrowboating world as you say we tend to choose fatter cables than are necessary from a current rating point of view (depends on the length though) and so the cable rating is rarely an issue when it comes to choosing fuse size. With a single operation device eg a water or shower pump, there is a certain current that it should take. If the current is much more, something is wrong eg it's jammed / stallled and it doesn't hurt to have a fuse rating that might blow after a while under those circumstances, to avoid the device overheating.

 

Bottom line is to select a fuse in accordance with the manufactuer's installation instructions because the manufacturer might be basing their failure mode analysis not causing a fire, on having the fuse blow under fault conditions.

 

AC devices tend to be more complicated and have various modes that could draw various amounts of current, washing machine being a prime example. As I said earlier, having a fuse that closely matches the maximum power consumption doesn't protect most of the components that draw much less current but might take too much current and overheat whilst the water heating element is off, and hence the total power consumption might still be quite low as the flames start to lick...

Plus of course, the public is thick and stupid and having a variety of different fuse sizes is just too complicated!

Edited September 12 by nicknorman