Load shedding

My laundry center shares a 30A circuit breaker with an auxiliary boiler. Both pull 24A when in use. I have a rotary switch that allows me to use one or the other. When the auxiliary boiler goes off line the diesel boiler kicks in. This system has worked fine for years.

I am in the process of replacing the laundry center with new compact stackables. The problem, all new compact units have microprocessors. My fear is that every time I switch the power to the laundry I will have to reprogram the time and wash cycles. An easy answer to this would be a load shedding device that drops the auxiliary boiler when the dryer kicks in.

I see Paneltronics has a load shedding module. Does anyone have any experience with it or experience with another load shedding device?

tiltrider1 said:

My laundry center shares a 30A circuit breaker with an auxiliary boiler. Both pull 24A when in use. I have a rotary switch that allows me to use one or the other. When the auxiliary boiler goes off line the diesel boiler kicks in. This system has worked fine for years.

I am in the process of replacing the laundry center with new compact stackables. The problem, all new compact units have microprocessors. My fear is that every time I switch the power to the laundry I will have to reprogram the time and wash cycles. An easy answer to this would be a load shedding device that drops the auxiliary boiler when the dryer kicks in.

I see Paneltronics has a load shedding module. Does anyone have any experience with it or experience with another load shedding device?

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Laod shedding devices are common in RVs and work very well. I've got an obsolete Intellitec model in an older RV that performs quite well. I do recommend using a device designed and built for marine use.

tiltrider1 said:

My laundry center shares a 30A circuit breaker with an auxiliary boiler. Both pull 24A when in use. I have a rotary switch that allows me to use one or the other. When the auxiliary boiler goes off line the diesel boiler kicks in. This system has worked fine for years.

I am in the process of replacing the laundry center with new compact stackables. The problem, all new compact units have microprocessors. My fear is that every time I switch the power to the laundry I will have to reprogram the time and wash cycles. An easy answer to this would be a load shedding device that drops the auxiliary boiler when the dryer kicks in.

I see Paneltronics has a load shedding module. Does anyone have any experience with it or experience with another load shedding device?

Click to expand...

I would first see how the new washer and dryer behave. I'm sure there is lots of variation, but we always turned off the breakers to our laundry when not in use, and never had to do any reprogramming when power was restored. So there is hope it will just work. If you lost power in the middle of a cycle you might need to restart it, but I don't think that the problem you are trying to solve, right?


If I'm following you correctly, you want power to the laundry all the time, and you want to switch the electric boiler on and off so it's not running when you are doing laundry. Is that right? A load shed device would automate it. But you could also just rewire the rotary switch such that the laundry always has power and the switch just turns the power to the electric boiler on and off. Then as you are doing today, you just turn off the boiler while you are doing laundry. I'm pretty sure that would work, and would be a very easy change.

Simplest way to do that is use a relay, like a contactor.
When the device you always want to run comes on, have relay or contactor open the circuit to the thing you don't want to run. Energize the rely off whatever is turned on, a motor etc... to shut off power going to the other device.

This will work if its only two devices using power at the same time. You will leave power on all the time to one, but turn it off to the other if something that uses a lot of power turns on with the first device, like a motor or heating element.

A relay is fully automatic, no needs to turn switches manually.

Our dryer is 220 and water heater 110V. They are on separate breakers and feeds. Maybe an electric panel re-arranging would prove helpful.

Yep, why have an either switch for boiler/laundry. Just need an on/off for boiler, then laundry can stay energized. Just turn boiler off when doing laundry.

Twisted you are correct with all your assumptions. The rest of you are all making good points. In my mind I was trying to idiot proof it. I plan to test the current method on the new appliances first. I’m feeling more hopeful after twisted’s input.

I had not discounted the relay method. I was just expanding my knowledge base of load shedding. A simple on off switch to the boiler would work but I think I need to be more idiot proof givin the number of guests using the laundry equipment.

tiltrider1 said:

Twisted you are correct with all your assumptions. The rest of you are all making good points. In my mind I was trying to idiot proof it. I plan to test the current method on the new appliances first. I’m feeling more hopeful after twisted’s input.

I had not discounted the relay method. I was just expanding my knowledge base of load shedding. A simple on off switch to the boiler would work but I think I need to be more idiot proof givin the number of guests using the laundry equipment.

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You can get a contactor or relay pretty cheap, and as long as the amp rating is good, they are robust, no microprocessors, so should last forever. Just make sure the coil voltage matches the volts used in the device. And it becomes idiot proof which is a good thing.

Ebay has good prices.

sdowney717 said:

You can get a contactor or relay pretty cheap, and as long as the amp rating is good, they are robust, no microprocessors, so should last forever. Just make sure the coil voltage matches the volts used in the device. And it becomes idiot proof which is a good thing.

Ebay has good prices.

Click to expand...

I think the challenge he will have is that we wants to leave the washer powered on all the time. In that case, what will trigger the relay? I doubt he wants to crack into the washer to find a point. The other approach would be a current sensor on the washer line, but those start to get a lot more expensive and trickier to get set points right with time delays and hysteresis.....

tiltrider1 said:

Twisted you are correct with all your assumptions. The rest of you are all making good points. In my mind I was trying to idiot proof it. I plan to test the current method on the new appliances first. I’m feeling more hopeful after twisted’s input.

Click to expand...

In that case, doing nothing and using the existing switch just as you have been using it would be really easy My kind of a job.

twistedtree said:

I think the challenge he will have is that we wants to leave the washer powered on all the time. In that case, what will trigger the relay? I doubt he wants to crack into the washer to find a point. The other approach would be a current sensor on the washer line, but those start to get a lot more expensive and trickier to get set points right with time delays and hysteresis.....

Click to expand...

There must be a motor or something that uses a lot of power that comes on, and that is what you would have to connect the relay coil up with.
You would leave the device fully powered on all the time so you would not lose the settings.

I am sure there is a service panel and then you have to run a small wire from there out to the relay for the signal to open the circuit to the other appliance.

So it would be a SPDT or DPDT type power relay rated for the proper amps, so when the relay coil is energized, it open circuits the other device. I think it is the cheapest simplest way to shed the load. Some kind of load shedding circuit sensing equipment is going to cost a lot more money, I would think.

Only thing in laundry that eats power is the dryer heat elements. You could power boiler disconnect contactor from there. A relay with NC contacts.

sdowney717 said:

There must be a motor or something that uses a lot of power that comes on, and that is what you would have to connect the relay coil up with.
You would leave the device fully powered on all the time so you would not lose the settings.

I am sure there is a service panel and then you have to run a small wire from there out to the relay for the signal to open the circuit to the other appliance.

So it would be a SPDT or DPDT type power relay rated for the proper amps, so when the relay coil is energized, it open circuits the other device. I think it is the cheapest simplest way to shed the load. Some kind of load shedding circuit sensing equipment is going to cost a lot more money, I would think.

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Agreed. It’s just that most people wouldn’t want to crack open the appliance for such a hack, and I say hack in a good way, not a bad way.

We have a RV that came with a load shedding 30 amp power system. It was a piece of crap. We could never get it to work well so I finally had the coach rewired to 50 amp service, problem solved.

I should have the dryer installed late tomorrow (Saturday). This will allow me to test my current set up. If that fails to satisfy the wife then I am thinking of trying Paneltronics load shedding unit. I am not as price sensitive as some. If that is unsatisfactory then I will find a way to tap in to my dryer motor. When the motor sees power it will pull the relay on the boiler. If these weren’t brand new units with warranty I would be less concerned about hacking into them. I would hate to void the warranty on day one.

I have bought many open frame power relays and put them in boxes Does not have to be fancy.
For one, I took 2 square metal boxes and sandwiched them together with the open frame relay inside using the 4 screw hole tangs meany to hold the switch or outlet holding the 2 halves together..

Here is a 30 amp rated relay 120v coil
https://www.ebay.com/itm/Magnecraft...h=item25e8a1fe19:g:z10AAOSw6dNWSmH1:rk:3:pf:0

Turns out the machines turn themselves off when not in use. They don’t even know I’ve cut the power. I can continue to use my existing setup.

Not much room to spare

I love projects that require no work. Glad it worked out.