Relay in washing machine circuit

kwired

Electron manager
Location
NE Nebraska
Here's what I found: there was a timer on the wall of the laundry closet (stack washer/dryer, 230v) that controlled the dryer outlet and a dryer vent booster fan. Customer just didn't know the timer was there. I'm guessing the booster fan is used for more then one unit, and management doesn't want it running unless it's needed, hence the timer/relay interlock.

See or learn something new all the time.
Would seem to me that either a current sensing relay or an air pressure switch would be a better way to control the booster fan, otherwise the setup you are describing limits when the dryer can be run, and runs the booster fan even if the dryer is not running.
 

gar

Senior Member
131027-1052 EDT

What does the word "timer" mean? Is this a time of day control, or a run time timer?

The location is CA, and I hear that there may be time of day pricing. If the timer is a time of day control, then this could be to force operation at a low cost time.

If it is simply a delay to off, then possibly to reduce long running time to reduce cost. Not very likely.

More information is needed.

.
 

kwired

Electron manager
Location
NE Nebraska
131027-1052 EDT


The location is CA, and I hear that there may be time of day pricing. If the timer is a time of day control, then this could be to force operation at a low cost time.
.

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Might not work so well for the tenant that has conflicting work hours with when the lower cost hours occur.
 

gar

Senior Member
131027-1138 EDT

kwired:

Both my washing machine and dryer can be put into the on state with no power, and when power is applied they will start. If power fails they stop, and restart where they left off when power is reapplied. Mine do not have the new electronic junk. The word junk does not mean that electronic controls can not be made to be as or more reliable than the electro-mechanical units. My experience and many others is that some new stuff is not more reliable or effective.

I have continuously running pilot lights on my furnace and water heater. Virtually no problems over many years. Gas range top electric ignition does not work real well.

I have a GE wall oven that works fine except when turned off at its control panel it wants to randomly beep. Thus, the breaker switch is off virtually 100% of the time. I have a GE microwave that likes to turn itself back on after a timed function has completed, the door is opened, the contents removed, and the door reclosed. Nothing clears this except pulling the plug for a few seconds.

The washer and dryer are old Maytag, about 15 or more years old. Virtually no problems except belts once and a seal leak. Also the washer washes clothes, and has a better transmission than the new models.

And energy efficiency is of no importance if the machine does not reliably perform its intended function. Such as washing machines that don't wash, and toilets that require multiple flushing.

.
 

kwired

Electron manager
Location
NE Nebraska
131027-1138 EDT

kwired:

Both my washing machine and dryer can be put into the on state with no power, and when power is applied they will start. If power fails they stop, and restart where they left off when power is reapplied. Mine do not have the new electronic junk. The word junk does not mean that electronic controls can not be made to be as or more reliable than the electro-mechanical units. My experience and many others is that some new stuff is not more reliable or effective.

I have continuously running pilot lights on my furnace and water heater. Virtually no problems over many years. Gas range top electric ignition does not work real well.

I have a GE wall oven that works fine except when turned off at its control panel it wants to randomly beep. Thus, the breaker switch is off virtually 100% of the time. I have a GE microwave that likes to turn itself back on after a timed function has completed, the door is opened, the contents removed, and the door reclosed. Nothing clears this except pulling the plug for a few seconds.

The washer and dryer are old Maytag, about 15 or more years old. Virtually no problems except belts once and a seal leak. Also the washer washes clothes, and has a better transmission than the new models.

And energy efficiency is of no importance if the machine does not reliably perform its intended function. Such as washing machines that don't wash, and toilets that require multiple flushing.

.
Most dryers for a very long time have been designed with a holding circuit through a centrifugal switch in the motor. Motor stops, the switch opens and will not start again until manually pressing the start button and holding it long enough for the centrifugal switch to close again. This may be different on newer appliances with electronic controls IDK.
 

GoldDigger

Moderator
Staff member
Most dryers for a very long time have been designed with a holding circuit through a centrifugal switch in the motor. Motor stops, the switch opens and will not start again until manually pressing the start button and holding it long enough for the centrifugal switch to close again. This may be different on newer appliances with electronic controls IDK.
That functionality, whether by centrifugal switch or electronic controls, is required by CPSC and probably UL listing for a dryer since some time in the distant past.
The two goals I am aware of are to prevent an unattended dryer from starting with fire risk and to prevent the dryer starting when a kid climbs in and closes the door.
The latter is particularly important if there is an electric door lock.
 
131027-1052 EDT

What does the word "timer" mean? Is this a time of day control, or a run time timer?

The location is CA, and I hear that there may be time of day pricing. If the timer is a time of day control, then this could be to force operation at a low cost time.

If it is simply a delay to off, then possibly to reduce long running time to reduce cost. Not very likely.

More information is needed.

.
A simple spring wound timer, delay to off.
 

kwired

Electron manager
Location
NE Nebraska
That functionality, whether by centrifugal switch or electronic controls, is required by CPSC and probably UL listing for a dryer since some time in the distant past.
The two goals I am aware of are to prevent an unattended dryer from starting with fire risk and to prevent the dryer starting when a kid climbs in and closes the door.
The latter is particularly important if there is an electric door lock.
How does Gar have one that will start on it's own after a power interruption? Import maybe? I have never seen one that would start automatically, most washers with mechanical timer I've seen will resume from wherever they were at in the cycle after power interruption.
 

dhalleron

Senior Member
Location
Louisville, KY
I suggest sending your post to one of the mods for editing; have him substitute "guy" for "electrician" from the first two sentences.

It would help me maintain an optimistic outlook on the future of the electrical trade. sigh....
I have worked over 30 years off and on with a "guy" that is also a licensed electrical contractor. He is good at what he knows and he always tries his best to do a correct, neat job and make the customer happy. He probably wouldn't have know what tis relay set up was. I could have figured it out.

There are things he doesn't know. He either steers clear of them or calls me. If I can't answer his question he will refer the job to someone else.

There are plenty of things I don't know. I either ask you guys, Google it or pass on the project.
 

gar

Senior Member
131028-1121 EDT

kwired:

I made a mistake in saying my dryer automatically restarted on power loss. It was from memory and confusion with the washer, and I should have run the experiment before making the comment from a not so accurate memory.

So my washer does automatically restart on restoration of power, the dryer does not.


electricguy61:

One needs to find out why this timing function was provided. Do other neighbors have a similar setup, or not?

The reason for the relay or contactor is that the switched current is moderately large. What controls the relay coil is going to detemine how the circuit functions.

If the only control to the relay coil is the timer, then the circuit is the equivalent to a timer with large contacts.

If something additional to the timer can supply power to the relay coil, then it is necessary to find out what it is and why?

Suppose that all we have is a high current off timer that controls power to both the washer and dryer. If there is an exhaust fan also powered from this timer, then the circuit would force the fan on only when it was possible for either or both washer and dryer to run. If all components are good, then this would imply that the dryer could not run when there was no power to the fan.

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