Hotpoint TDC30p motor cuts out when heating

[freddofrog]

Hotpoint TDC30p motor cuts out when drying, but not if started in the 10 minute cool-down cycle.
In drying cycle, when the motor cuts out, the timer keeps going, and the motor comes back on briefly then cuts out again, and this continues into the cool-down cycle.
But if started in the cool-down cycle, it is ok, even if cool-down is quickly repeated again.
I wish I had a service manual to be able to figure this out myself, it’s a mystery otherwise, anyone got any ideas ?

[Martin]

Re: Hotpoint TDC30p motor cuts out when heating

Start Relay or Thermal trip in motor windings maybe?

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

Another test that I’ve just done.

If I over-ride the door micro-switch and run the dryer empty with the door open, then it runs ok i.e. with heat blowing straight out into the room, the drying cycle is ok.

But if I shut the door, then that is when the problem starts (after a few minutes).

N.B. there is no fluff in the door, or on the filter, or in the condenser.

So is the front thermostat faulty ?
Or is the condenser faulty (hot air escaping into the dryer cabinet) ?

[iadom]

Re: Hotpoint TDC30p motor cuts out when heating

Martin wrote:Start Relay

What he said. 😉

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

I’ll order this one then
http://shop.ukwhitegoods.co.uk/1701624- … ryer-relay

thanks guys.

Just curious, is it being affected by heat then ??
i.e. if the chassis/cabinet is staying cool, it runs ok

[Martin]

Re: Hotpoint TDC30p motor cuts out when heating

The contacts arc and get pitted over time. Sometimes the terminal contacts within fail too. High current relays fail….period. Not fixable, cheap to replace so scrap and buy a new one the way forward.

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

Hi Martin
Before committing to buy a relay, I checked the voltages on the relay terminals when the motor has cut out.

The door micro-switch takes neutral to the “on” button, which then takes neutral to the relay coil, which is latched by one pair of contacts.
The other pair of contacts take neutral to the motor, and neutral is still present on both those contacts when the motor has cut out. So I guess I better take the side panel off and find a place to check that both live and neutral are going into the motor when it is not rotating.

You mentioned a thermal trip in the motor, does that automatically reset iteslf when tripped ?

Rather than buy a new motor (~£88), can I easily get at the thermal trip and replace it ?

cheers, Brian

[Martin]

Re: Hotpoint TDC30p motor cuts out when heating

freddofrog wrote:So I guess I better take the side panel off and find a place to check that both live and neutral are going into the motor when it is not rotating.

That seems like your best and most obvious way forward here.:wink:

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

LOL

I’m an electronics engineer with a couple of decades experience, but this is the first time I’ve ever tried to fix a condenser tumble dryer. As I mentioned in the beginning, if I had a serivce manual (with schematic diagram) this would be easy.

Anyway, I’ve removed the side panel, unplugged the heaters, and put it on a 120 minute drying cycle (empty). Half-way through and it’s still running fine, so it does have something to do with heat.

There must be a seal between the fan that circulates the hot air, and the motor (same housing for both). So my guess is that if there is a thermal cut-out in the motor, then it must be tripping because heat is getting past the seal into the motor.

I’ll post an update when I’ve found out if it is that, or anything else, in case anyone else does a search with a similar problem.

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

hmmm, I thought I better check the live & neutral into the motor with the heaters plugged in. After 10 minutes, the live(s) to the motor disappear. There are two live feeds to the motor (fwd and rev), they come from the mechanical timer. If it’s contacts in the timer that are the problem I don’t see why heat is the cause, however I think that the timer feeds a live coming up from where the front thermostat is …. could be that all along. But it would be crazy to have an over-heat sensor at the front of the drum that only cuts power to the motor. That’s it for now, too many stupid coloured wires in there LOL

[iadom]

Re: Hotpoint TDC30p motor cuts out when heating

The stats do not cut power to the motor, only the heater.

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

iadom wrote:The stats do not cut power to the motor, only the heater.

aye that makes total sense, and from that logic I can see why you and Martin suggested the relay, or a thermal cut-out in the motor.

I’ve taken photos of all the connections, removed all the tie wraps, and taken out the timer.

There’s a “thing” ❓ on the end of the timer, that has a pair of wires coming round to where all the terminals are on the timer, and there was basically no connection to one of the pairs on the “thing” (I don’t know what it is supposed to do).

I’m going to connect a live and a neutral to the timer and check the terminals with the timer running, I suspect that someone has been in this dryer in the past and not put one of the connections back onto the correct terminal (my son got this dryer in this condition from a friend of a friend :rolls: so I don’t know its history). Dodgy repair-man in the past methinks :clown: (and I’m beginning to think that I should buy the service manual from Hotpoint :eeek: ).

[iadom]

Re: Hotpoint TDC30p motor cuts out when heating

I assume you mean the timer motor when you say ‘thing’. There will not be any wire going to one the the terminals that the timer wires go to, it has internal connections as well. 😉

And a manual will cost you more than a relay. If everything was working, heating, tumbling etc then I would suggest that all the wires are, or at least where on the correct terminals.

Sent from my iPad using Tapatalk HD

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

iadom wrote:I assume you mean the timer motor when you say ‘thing’. There will not be any wire going to one the the terminals that the timer wires go to, it has internal connections as well. 😉

And a manual will cost you more than a relay. If everything was working, heating, tumbling etc then I would suggest that all the wires are, or at least where on the correct terminals.

Sent from my iPad using Tapatalk HD
aye the “thing” must be the motor 😳

well these are the symptoms …
1. with heaters unplugged in the loom, the dryer runs (empty)until manually stopped (I ran it more than an hour)
2. with heaters plugged in, the motor cuts out after about 10 minutes. Both of the live feeds (fwd & rev) to the motor are cut, they originate on the timer. The front drum thermostat feeds live to the heaters, and also plugs onto a terminal on the timer. The timer continues to run. Note also that the neutral feed to the motor comes from the relay and is ok.

So the problem is definitely related to heat, it is not the relay, it is not the motor.

[freddofrog]

Re: Hotpoint TDC30p motor cuts out when heating

I’ve had the timer running on a desk and checked the way the terminal connections vary during timer running, and from what I can see, the way everything was connected to the timer was correct.

Although I haven’t made a circuit diagram of the complete dryer, from the sketche I’ve made of the timer, there is only one logical explanantion for what it going on ….

When high currents for the heaters are being drawn across contacts in the timer, it must cause the contacts to the motor to disconnect for some reaon. Now that I’ve taken the timer out, all that I can do is put it back and check the voltages on the various timer terminals while everything is running, and I reckon I should see the “live” feeds to the motor disappear, but everything else remain unchanged (the stats in the heater at the back would also open fairly quickly but that won’t be observable from the timer)

Anyone know where to get a timer at a cheap price ?

[Author]

Posts