Lyman Mag 20 cutting out.

[dromia]

I've acquired an old Lyman Mag 20 Furnace. You plug it in, switch it on, light comes on and it starts heating up then when it seems to reach a certain temperature it blows the fuse. The alloy isn't melted when this happens.

I'm no sparky but it seems like a thermostat issue, any ideas observation or someone had the same problem. If it is a costly fix then the furnace isn't worth it

Sending back to Lyman isn't an option seeing as how I'm in the UK.

[williamwaco]

How about a small appliance repairman.
Anyone who could fix a thermostat on an oven should be able to fix the thermostat on that pot.

[Le Loup Solitaire]

The thermostat housing has to be opened up for at least a visual inspection. Then by using a "continuity tester" the thermostat has to be tested in various spots including the point where the cutting out occurs. There may be s short at that spot. A tester of continuity usually has a resister and a signal light as part of the circuit so that you can see when current is present and the resistance keeps the fuse from popping if there is a short. Parts are probably obtainable on this side of the pond and someone can order what is necessary and mail it/them to you. LLS

[Mal Paso]

It's not a 120 volt unit is it?

It may not be the temperature of the pot, rather the length of time it takes for the fuse to blow at that amperage.

I can't imagine a thermostat that would short upon opening.

[jsizemore]

I assume you don't have a meter to test with or know what it means?

You can bypass the thermostat and do a direct hookup to the element. Plug that rascal in and see if it melts lead. If it melts then the thermostat is the culprit. If the fuse blows then the element or cord is questionable.

[Rockchucker]

I assume you don't have a meter to test with or know what it means?

You can bypass the thermostat and do a direct hookup to the element. Plug that rascal in and see if it melts lead. If it melts then the thermostat is the culprit. If the fuse blows then the element or cord is questionable.


I really don't see how the thermostat is blowing the fuses, all it is, is a set of contacts that open and closes. It consumes no energy at all. If you don't have access to am amp meter to monitor the amp draw I'd open up the cover and look for a loose connection. Second thing I'd check for is the fuse size and type, they may be old or undersized. When buying fuses look for the Fusetron type. They have a time delay built into them. Hope this helps /Ron

[jsizemore]

Hey Ron,
I got a call back today on a GE Profile cooktop. Weekend before last the lady of the house was boiling chicken to make chicken pastry. It boiled over a little and after another 15 minutes it tripped the breaker. Of course they checked the panel in the house and didn't even know about the 2 panels by the meter base. She told me about it not working and no breakers tripped. I said it may be a control wire or primary wire blew out from being in standing water contained in the internal sheetmetal or control switch. Since the cooktop was less then 5 years old she decided to contact GE about an authorized technician. Well she decided to take a week off from cooking and didn't call GE till this past weekend. They said they would give here a list of authorized techs and it was up to her to arrange repairs. There was a minimum service charge and GE might cover the parts depending on what they discovered.
So Monday she tells me since I know where the house key is to go fix it! Of course I find the tripped outside breaker and do a function test on all burners and exhaust fan. Burners on high for timed 5 minutes with exhaust running and all is well.
She calls last night and says she was heating up a pan to cook and there was a flash in the vicinity of exhaust fan intake and the burners went out. I had her husband check the outside breaker and he said it was 'ON'. I got there this morning and sure enough the cooktop isn't working. I send the husband out to turn off the breaker and then dive under the counter to dismantle the beast. My first GE Profile of this model. I checked each of the burner controls for water and nothing. Burners are sealed to the bottom of the cooktop so the don't have water. I figured after a week the slop trays under the burners should be dry. I disconnected the quick release plug from the downdraft fan and told the homeowner to turn on the breaker. As soon as it went on there was a flash at the fan switch and no power. I told the homeowner I knew what it was and went outside to turn off the breaker cuz he said it was on. The breaker was in the on position but had only tripped one leg of the 240 breaker and wasn't strong enough to overcome the other leg in the on position. What happened was chicken fat had got into the fan switch and after it would heat up it would ooze inbetween the power supply connector and the clip that held the switch together and provided ground.
I have seen folks use about anything at hand to fix appliances. Regular crimp on crimp connects instead of hi-temp. Become loose from being overheated and cause arcing and burn the spade right off and the supply wire go to ground. Ants go for the gold in a contactor and so many ant exoskeletons that the contactor couldn't make. Mega dead rodents in the works.
When I suggested that dromia bypass the thermostat that would give him the oppurtunity to open the inspection cover reroute some wires and check connections. No moving parts in the cord or element. They either work or don't. Sometimes you can get a noobie to break into control switch but I try to save that for last.
Next we'll work on the flip-flop wiring for a 36volt service truck crane that gets charged by a conventional 12 volt system. Or Nelson Pass Zen amplifiers?

[Mal Paso]

What happened was chicken fat had got into the fan switch and after it would heat up it would ooze inbetween the power supply connector and the clip that held the switch together and provided ground.


I love it!

I wonder if he is overdrawing the fuse and that's how long the fuse delay is.

Does he somehow have a 120 volt pot which over there would be a 1400 watt pot.

Im curious now!

[Woodshot]

Dromia,
The pot is melting the lead okay now, got a new fuse for the unit, the problem with it now is the
spout could be blocked, as it is not pouring. Having our man look at it ASAP.
Jim

[dromia]

Unblocking the spout isn't a problem. Even I can do that Jim.

Its had a lot of fuses replaced, its what is blowing them that I'm interested in?

[dromia]

Evidently it was an internal fuse within the pot that was causing the plug to fuse. The internal fuse has been replaced and the pot has been successfully melting lead staying on for 3 hours without any problems.

Thank you all for your help and suggestions both here and by PM.