Pool Timer for 240 V Space Heater

[mcman56]

I have a stand alone 240 volt 30 A space heater for the garage and would like a delay off timer but none are available. I also use this outlet for a mid welder if that matters. It looks like I may be able to use a pool timer with a change but would like to clarify what I currently see on my pool. See pictures. My timer seems to be wired by per the instructions on the cover except that one of the 240 V leads goes out of the box on the right and through a 120 V 20 amp light switch before returning to the box. Is it correct that this switch would only need a 120 V 20 Amp rating on my 240 V 30 amp application? If so I could just use a 120 V timer in place of the switch.

I realize that the pool is a lower amp application and the wires are too small. I also realise that the 24 hour timer then has no purpose but I could set it to shut down at night when not in use. I'm just wondering if a similar set up would work for a space heater.

My 1.0 version for this was a transformer, contactor and 120 V timer built into the heater. After quite a bit of use multiple wires got fried. This could have been failure of one of my crimps so I'm reluctant to do crimping on this kind of power again. Some OEM crimps got cooked as well as some of mine so it could also have been something else. This is was a 13 year old DR Heater that I now replaced.

 

[mcman56]

A timer like this.

https://www.intermatic.com/Product/FF4H?setcontextlanguagecode=en

 

[wyliesdiesels]

well its rated for 40a resistive loads so...

 

[mcman56]

The big question for me is if it is acceptable to use 115 volt 20 amp timer on one leg of a 240 volt 30 amp heater circuit.

 

[mm08822]

The big question for me is if it is acceptable to use 115 volt 20 amp timer on one leg of a 240 volt 30 amp heater circuit.

The time clock label states it is rated for 40amps with a resistive load from 120-480vac. Your load is less than 40a so it is ok to use.
Why not interrupt both legs, the clock has 2 poles.

From a control perspective, breaking 1 leg is fine.
From a disconnect perspective, both legs need to be broken (not that i would trust a time clock for that.)

 

[nadogail]

I used a similar timer to control when my son charges his Nissan Leaf. He gets to plug it in during the day and charge after the rate changes to Super Off Peat.

 

[johnre]

The big question for me is if it is acceptable to use 115 volt 20 amp timer on one leg of a 240 volt 30 amp heater circuit.

Use something like this and drive it with the timer - the primary side of this contactor is 120 V:

 

[Bert_]

The big question for me is if it is acceptable to use 115 volt 20 amp timer on one leg of a 240 volt 30 amp heater circuit.

Where are you coming up with 115v 20A?

Your pool timer is a good intermatic time clock rated for a 40 amp resistive load. The contact is rated all the way up to 480 volts. The clock motor is correct for your 240 volt application.

 

[mcman56]

My current pool pump set up breaks one leg of the incoming 240 volts with a 115V 20A switch. That is the highest rating I see on the mechanical timers. I even contacted Intermatic.

For version 1.0, I used a transformer and a contact inside the heater housing along with a timer on the 24 V circuit. All worked well for a year of occasional use in the garage so a wild guess is 200 to 1000 hours. It started to smell for a few days and then quit. Multiple wires were burnt at the connectors, some were my crimps and some the OEM. The heater was 13 years old. All of the individual components looked OK. I even cut open the transformer to see if it looked OK inside and it did. I don't have any spec on the heating coil to test resistance. Since I don't know the failure mode and have no experience with things like this I suspect that maybe one of my crimps failed so would like to stay away from something that requires me to crimp on connectors. Any guesses at failure mode would be appreciated. I just bought a new heater but would still like a timer.

 

[mm08822]

The T104R timer label you posted handles 40a @240vac. Just get another identical time clock and dedicate it to the heater.

Why would you use crimp terminals in the power circuit when set screw lugs are present?

There are off delay timers available that can be incorporated into a 3-wire control scheme to drive a contactor. You would need to close the control circuit with a momentary on pb.

A simple disconnect ahead of the heater would make this a lot easier for you.

 

[mcman56]

A pool timer is the only option I see. However I would like a delay off timer like for a whole house fan that could be set for X hours rather than having to deal with time of day on a pool timer.

Crimp terminals would be for any solution using a contactor like version 1.0, at least all of the contactors I see.

The heater is a plug in like a dryer so no other disconnect needed. I even looked for a WIFI control timer like those available for 120 v but don't see one.

 

[Bert_]

My current pool pump set up breaks one leg of the incoming 240 volts with a 115V 20A switch. That is the highest rating I see on the mechanical timers. I even contacted Intermatic.

For version 1.0, I used a transformer and a contact inside the heater housing along with a timer on the 24 V circuit. All worked well for a year of occasional use in the garage so a wild guess is 200 to 1000 hours. It started to smell for a few days and then quit. Multiple wires were burnt at the connectors, some were my crimps and some the OEM. The heater was 13 years old. All of the individual components looked OK. I even cut open the transformer to see if it looked OK inside and it did. I don't have any spec on the heating coil to test resistance. Since I don't know the failure mode and have no experience with things like this I suspect that maybe one of my crimps failed so would like to stay away from something that requires me to crimp on connectors. Any guesses at failure mode would be appreciated. I just bought a new heater but would still like a timer.

What switch are you talking about? The only switch in an intermatic timer is the contact inside the timer. A lot of them are 40 amps.

Your pool timer has a light switch that the installer added on the side. If you want a switch to disconnect power you have many options.

 

[hobie18]

Against my rules, a friend wanted to use an extension cord to power his small a.c. (5,000 b.t.u., tiny studio apt.) Cord was just a bit too short to reach the outlet.

 

[PCustoms]

Against my rules, a friend wanted to use an extension cord to power his small a.c. (5,000 b.t.u., tiny studio apt.) Cord was just a bit too short to reach the outlet.

Ok?

 

[hobie18]

Now he needs a new a.c.

 

[75gmck25]

I seems the 40 amp Intermatic water heater timers might work for what you want. Most models are designed to set at least two "on" and two "off" times each day, and also have a manual "on" switch. If you switch it on manually it believe it will automatically shut off at the next timer-"off" setting.

 

[dave*99]

I believe the OP wants to crank the heater on with a timer and let it run for a count down period, much like a bathroom fan. I suspect the clock type is not exactly what he wants. His comment about contacting Intermatic and not finding a 30A unit was likely based on their line of spring wound timers.



If you have the budget, there is a solution.



A cheaper solution would be to drive a contactor with the Intermatic spring wound timer.

This may also fill his needs:

https://www.amazon.com/DEWENWILS-Outdoor-Wireless-Controller-Compatible/dp/B07PP2KNNH/?tag=atomicindus08-20

 

[hobie18]

Ok?

Growing up a tragedy occurred with a family that lived the house second from us. Just 25 feet away.
Their daughter and family had just moved into a new house. The parents, the ones who lived near us, bought them an air conditioner. Fire consumed them in the middle of the night.
More than 50 years later it still haunts me.

 

[wyliesdiesels]

I would like a delay off timer like for a whole house fan that could be set for X hours rather than having to deal with time of day on a pool timer.

You could build your own with a whole house fan timer and contactor.

 

[wyliesdiesels]

The parents, the ones who lived near us, bought them an air conditioner. Fire consumed them in the middle of the night.

How did the fire start?

 

[hobie18]

How did the fire start?

Sorry, was about to edit that in.

They used an extension cord to power the new air conditioner.

Neighbors went from happy family to devastated overnight.

 

[Bert_]

Extension cords themselves aren't necessarily bad. What you have to watch is the connectors. A worn out connector has high resistance and gets hot. It can happen to a receptacle in the wall too.

But it's hard to explain that to people. It's easier to just say "no extension cords"

I've seen window air conditioners with 2 cut off melted cord ends laying there and they are still using the same worn out receptacle in the wall. Gee I wonder why it keeps happening...

 

[hobie18]

Absolutely!
Yes, the connections are where most of the resistance issues come from. A well made and well specified cord could work. After all there is no guarantee the original cord is any better. But the additional connections and such...
Gold plating is used, not so much as a good conductor, (it is, and yes) but it does not corrode. Hi-fi, airbags, etc.

But as you say, it is easier to say no extension cords

 

[mcman56]

"I believe the OP wants to crank the heater on with a timer and let it run for a count down period, much like a bathroom fan. "

Exactly, so the old man (me) does not forget and leave it on. I'll look into those options. Thanks