eBIAB Wiring Question

[Medic192]

Hello All

First post here on the site. AWESOME information available.
I am in the process to build a eBIAB system with a 3kw element, timer and PID from Auberins. Using a 25Amp SSR.

I want to draw the wiring diagram but I have a question or two. The power we have is 220/240v and use 3 wires (live, neutral and earth).
I want use a key switch (2 pin ON/OFF) to power the whole control panel but it is rated at 6Amps. I was told that I would have to add a 20amp contactor so that I would be able to use the key switch?

If that is the case would the key switch be before or after the contactor?

My last question for now-I have a few 4 pin DPST 6Amp rocker switches that I want to use for switching the power on to SSR for element and for switching the pump on etc. How do they get wired? Live in and live out and neutral in and neutral out?

I will post the diagram once I am done with it.

 

[Leithoa]

Check out Kal's safety interlock page.

 

[Ahalla05]

When you say" 3 wire system" I believe you mean 2 hots and a ground which you give you your 240. Is there a reason you want to go with a key switch? My current mini panel I built just uses a 30a 240v toggle switch that can be picked up at the local Home Depot. Easy power on power off with out the need for additional equipment. But if your set on that key switch kal's page is just full of info!

 

[dscott]

The switch would be before the contactor... A contactor is simply a relay (an electrically activated switch) Remember (or learn) ohms law.
Also, 240 is a hot(120) + a hot(120) + a ground which is electrically equivalent to neutral. Neutral and ground are tied together at the main panel.

 

[barryhannah]

I'm guessing he's in a country with 240V supply (like myself in New Zealand). That means 3 wires, phase, neutral and earth.

@medic192, the key switch switches before the coil of the contactor. Power goes into the box, through switch, to coil, so when switch is on it energises the coil, the contactor makes contact and power flows through to the system.

Your second question, always switch on the hot leg, the phase. The neutral can go directly to the component. Simple reason for that is you don't want your component to be supplied with hot/current even when the switch is off. Make sense?

 

[Medic192]

I'm guessing he's in a country with 240V supply (like myself in New Zealand). That means 3 wires, phase, neutral and earth.

@medic192, the key switch switches before the coil of the contactor. Power goes into the box, through switch, to coil, so when switch is on it energises the coil, the contactor makes contact and power flows through to the system.

Your second question, always switch on the hot leg, the phase. The neutral can go directly to the component. Simple reason for that is you don't want your component to be supplied with hot/current even when the switch is off. Make sense?

@ BarryHannah

Thank you very much for the info. It all makes sense now. Forgot to update my profile with info where I am from. I am from South Africa and use the same wire configuration as you.