The electric dryer starts/runs fine…but will only blow cold air.
I have instaled new…thermal fuse (was blown), dryer cycling thermostat,
heating element with new thermal cut-off, and high-limit thermostat.
I have checked for 240v at the box and terminal block…both good.
While running in Perm.press high heat cycle, using a circut tester on the
timer I get 240v between Red and Blue, 120 between Red and Purple,
120 between Red and Orange, 120 between Red and White. Also checked
between Orange and Orange for resistor next to start switch, 120 also.
What’s left to check or replace?
Unplug the unit, set it mid-scale timed dry and check timer switch 2, it should be 0 ohms.
You could also attach one meter lead to Black (L1), leave it here and then work your way back through the heater circuit component by component using ohms.
If everything checks out OK to the far side of the heating coil (right side on the wiring diagram) then odds are either the centrifugal switch is not closing for some reason or the red is burned out somewhere.
Thanks for thr reply,
I only have a circut tester…Could I take the timer to the
local parts shop to be tested?
Is the centrifugal switch on the motor? And can I test it
without taking the motor out?
I only have a circut tester…
Since you have started repairing your appliances I would recommend you buy yourself a meter. If you had one earlier you would have been able to check the parts with it before replacing them. It will let you read AC volts (it is nice to know what the actual voltage is), DC volts (comes in handy checking batteries etc.) and resistance (ohms). If possible I always try to check parts using ohms why fool around with a live unit and risk a shock or an arc/spark if you do not have to.
Could I take the timer to the local parts shop to be tested?
They may do it for you problem is you have to know where it is set.
So if they rotate the shaft it is messed up.
Is the centrifugal switch on the motor?
Yes. There are two of them. A mechanism in the motor closes them when the motor gets close to operating speed.
One connects in the heating coil, it ensures that the coil does not come on until there is air flow.
The other disconnects the start winding in the motor as leaving it in circuit would overheat the motor. It’s normally open side is wired in para;llel with the start switch and it closes. This lets you release the start switch and the unit keeps running.
[COLOR="DarkRed"]
And can I test it without taking the motor out?[/COLOR]
Removing the motor does not gain you anything. It is a pain to test because the motor has to be close to operating speed for it to close. The easiest way is to eliminate the thermostats, heater and timer. Then all that is left is the centrifugal switch. It is the one with the 2 larger red wires going to it.
You could also do a live test. With the drum removed measure across the switch. Start up the unit, if you see 240 volts across the switch it is toast.
This is easiest done with two people so you can concentrate on the meter leads and someone else can start the unit. Do not run the unit very long as it will blow the thermal cutout if the heater comes on. There is no air flow over the heating coils with the drum removed so they will overheat…
If you attempt this be very, very careful as 240 volts is lethal!!!
You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
Always remove power from the machine otherwise you could blow your meter.
Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale’s dynamic range.
There is a good STICKY at the start of this forum about it’s use.
