relay circuitry help
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relay circuitry help
So I am trying to build a relay box with an electromagnetic relay, the "ice cube" type. Sadly SSR is not an option because of the controller type. These relays are standard for relay boxes that are used in residential heating systems...so I figured I could just copy that. However, there seems to be a resistor in those pre-made relay boxes and I dont know why or where it goes. I know that the diode is to protect the relay from the collapsed magnetic field...but I dont know how to spec the right diode. So here is the store bought version and a sketch of my stab at the circuitry. Anyone that has a stronger electronics background than mine, I could really use the help!
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doughboyshredder
- Posts: 1354
- Joined: Mon Sep 17, 2007 7:37 pm
Why do you think an SSR won't work?
SSR stands for solid state relay, and an SSR can handle more current than an electromagnetic relay typically.
Those little icecube relays are not rated for the amperage that you need to pull through there. I can't see from the pic you posted. What does it say on the top of that relay?
SSR stands for solid state relay, and an SSR can handle more current than an electromagnetic relay typically.
Those little icecube relays are not rated for the amperage that you need to pull through there. I can't see from the pic you posted. What does it say on the top of that relay?
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doughboyshredder
- Posts: 1354
- Joined: Mon Sep 17, 2007 7:37 pm
O.K. I looked at the manual for that, and you are making this way more complicated than it should be.
First of all that is a 24vac relay. The contacts are rated at 7.2 amps. Depending on the size of your blanket this is probably significantly underrated.
For our application there is absolutely no need for the diodes.
Return that if possible. You don't need it.
Any controller will work with an SSR. What type of outputs do you have on your controller? Com and NO? Easy. Purchase a plug in transformer (Radio shack has them) Run one wire to the ssr run the other wire to Com then run a wire from NO to the other side of the ssr. 115v output from controller? Then purchase a 115v ice cube relay (again, Radio shack). Hook the 115v output from the controller to the coil on the relay. Again use a plug in transformer (same voltage as ssr). Run one leg of the transformer to the ssr and run one leg to com on the 115v relay, then run a wire from the NO on the relay to the other side of the ssr.
Does that answer your question?
You probably spent about 140.00 for that board. A plug in transformer is 20-30.00 and a relay is 15.00. Return it and do it right.
Just read closer and saw you haven't bought that. Good.
You need an SSR, a transformer that matches the voltage of the SSR, and depending on output type from your controller you may need an icecube relay.
Let me know what kind of output you have on your controller and I will draw the circuit for you.
First of all that is a 24vac relay. The contacts are rated at 7.2 amps. Depending on the size of your blanket this is probably significantly underrated.
For our application there is absolutely no need for the diodes.
Return that if possible. You don't need it.
Any controller will work with an SSR. What type of outputs do you have on your controller? Com and NO? Easy. Purchase a plug in transformer (Radio shack has them) Run one wire to the ssr run the other wire to Com then run a wire from NO to the other side of the ssr. 115v output from controller? Then purchase a 115v ice cube relay (again, Radio shack). Hook the 115v output from the controller to the coil on the relay. Again use a plug in transformer (same voltage as ssr). Run one leg of the transformer to the ssr and run one leg to com on the 115v relay, then run a wire from the NO on the relay to the other side of the ssr.
Does that answer your question?
You probably spent about 140.00 for that board. A plug in transformer is 20-30.00 and a relay is 15.00. Return it and do it right.
Just read closer and saw you haven't bought that. Good.
You need an SSR, a transformer that matches the voltage of the SSR, and depending on output type from your controller you may need an icecube relay.
Let me know what kind of output you have on your controller and I will draw the circuit for you.
Ok, like you said, I have not purchased that relay box, only using it as a guideline for what I am trying to do. First off, I have built a couple of the typical heater setups as shown in the skibuilders articles. This is different. The relay will not be running high voltage, it will be running a pump. I initially tried to use an SSR and without any luck (tried two different SSRs). I was told that the reason the SSRs would not work is that I am not using a solid state controller (I am guessing the usual omrons skibuilders use is that), instead I am using a thermostat so it lacks an SCR controller (no idea what that is) and therefore needs to be controlled with an electromagnetic relay. The way I am trying to heat is a bit different than the usual heat blanket setup, but I know I am close with the diagram.
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doughboyshredder
- Posts: 1354
- Joined: Mon Sep 17, 2007 7:37 pm
What wasn't working with the SSR?mattman wrote:Ok, like you said, I have not purchased that relay box, only using it as a guideline for what I am trying to do. First off, I have built a couple of the typical heater setups as shown in the skibuilders articles. This is different. The relay will not be running high voltage, it will be running a pump. I initially tried to use an SSR and without any luck (tried two different SSRs). I was told that the reason the SSRs would not work is that I am not using a solid state controller (I am guessing the usual omrons skibuilders use is that), instead I am using a thermostat so it lacks an SCR controller (no idea what that is) and therefore needs to be controlled with an electromagnetic relay. The way I am trying to heat is a bit different than the usual heat blanket setup, but I know I am close with the diagram.
What kind of outputs do you have from your controller?
What is the voltage on your pump?
What is the amp rating on your pump?
What is the inrush current draw on your pump?
Basically, what does the nameplate say on your pump?
The SSR was providing the pump with what appeared to be sporadic current...enough to run a jigsaw, but not enough to run a pump. The controller acts as a switch. The current source is a transformer, like the one shown on the left hand side of the Argo unit. The pump is 115V, 60Hz, 2uF, .22A, 25W.
Last edited by mattman on Thu Nov 03, 2011 7:01 am, edited 1 time in total.
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doughboyshredder
- Posts: 1354
- Joined: Mon Sep 17, 2007 7:37 pm
what you're describing is symptomatic of the controller or power being provided not the ssr.
The thing with pumps / motors is that depending on the type of motor your inrush current can be as much as 7 times your run current. So for a 5 amp motor your inrush current can be up to 35 amps.
All of this info is posted on the nameplate of the motor for the pump.
The thing with pumps / motors is that depending on the type of motor your inrush current can be as much as 7 times your run current. So for a 5 amp motor your inrush current can be up to 35 amps.
All of this info is posted on the nameplate of the motor for the pump.