Use of Coils in Control Panel

[chewse]

Let me start by saying I'm not an electrician nor very good at doing electrical related projects. So....I've decided to build a control panel which would be used to manage a RIMS tube element, HLT element, Boil temp (I'm still using gas), and pump. I've viewed several electrical diagrams from PJ, Kal and the Electric Brewing Supply co.

I may be over simplying this question but is one 240v-30A 120 V coil needed for each of the elements? (RIMS Tube element, HLT element). And, can you tell me why a coil is needed. Since I'm not using an element for the Boil, I assume I don't need a coil.

 

[stlbeer]

Chewse, you're looking at a contactor rating. The contactor is rated for carrying up to 240v and up to 30A. There is an eletromagnetic coil that flips the engages/disengages the contactor - it is rated at 120v. i.e. it uses 120v to switch a higher current.

 

[aboantopick]

I have the same question.
I have planned a PID that sends a low voltage message to a 25 AMP SSR that supplies the 2000 watt heating element with 120 voltage. So what do I need a contactor coil for?

 

[BigFloppy]

I have the same question.
I have planned a PID that sends a low voltage message to a 25 AMP SSR that supplies the 2000 watt heating element with 120 voltage. So what do I need a contactor coil for?

The contactor would be an enabler (override) to allow / stop power getting to the heater element or SSR - SSR's have a habit of failing closed rather than open... it's a peace of mind scenario

 

[P-J]

A lot of the switches (check out the illumiated switches from Auber Instruments) cannot carry the high current needed to power the element. A contactor solves the issue.

P-J

 

[augiedoggy]

The contactor would be an enabler (override) to allow / stop power getting to the heater element or SSR - SSR's have a habit of failing closed rather than open... it's a peace of mind scenario

A contactor or relay is also dual pole in this case so it allows you to kill all the power going to your element..... I you don't use one you will have one leg of your 220 circuit that's always live going to the element when the power is on... The contactor makes it easy to wire in a selector switch to prevent both elements from firing if you have a 30a power source such as a dryer outlet that your using.

They are only $10 a piece with shipping from eBay and worth every penny....

I used smaller omron relays with 24v coils instead since my pumps also run on 24v and I have the power supply in my control panel.

 

[chewse]

Thanks for the info everyone.