Please check my wiring diagram

[ComeOnNow]

Hi,

I'm a technologist by trade, but not an electical engineer. Please review my wiring diagram, and let me know if I am missing anything. It is for a single PID, single vessel system, with 1 on/off switch, an emergency stop, a "power on" LED, and an indicator light for when the PID is firing the element.

Thanks in advance.

 

[jCOSbrew]

I would replace the dpdt switch with a contactor and have an estop control the contactor coil.

Also consider moving the 220 element light to the output of the ssr (at the element connector)

Add a switch and use the 110 light for a pump.

 

[ComeOnNow]

Thanks for replying. I'm not planning on using a pump. As far as the lights, I wanted to use one light to show when the control panel had power (which is why I had it where the hots are coming in. And the 2nd light (which was a late addition) was to show when the pid was firing the element.

Why do you recommend connecting the on/off switch to a contractor? Is it just so I wouldn't be manually hitting the power lines? I only ask because the switch is rated at 25amps, so I assumed that is what it was for.

I already purchased all of the components, I just haven't started piecing everything together, so it's not too late to add things. In the end though, I kind of feel like this is turning into a money pit, and I should have just picked up one of those basic Pwm type controller kits from high gravity. Curses! Oh well, at least I'm learning a lot of new stuff.

 

[BadNewsBrewery]

A switch or contactor after the SSR but before the outletwould be nice, maybe repurpose the one you have before the PID? SSRs are known to leak trace amounts of power, and can fail in the energized state - a switch / contactor between the SSR and the outlet gives you a manual means of disconnecting power. With the switch only controling one PID as it is now, you could do the same thing by just plugging in / unplugging the panel.

-Kevin

 

[jCOSbrew]

If you run out space on the panel for lights, you can tell when the panel has power because the pid is on. The pid will have a small led to indicate the SSR output is on.

 

[ComeOnNow]

So the on/off switch AFTER the SSR (right before the element)? Would I be safe using just the 25a On/Off switch, or would I need a contactor?

I only put the on/off switch at the beginning, b/c it made sense to me to want to cut the power going into the box, not just going into the element.

Also, I think I screwed up on the diagram. I put in Hot/Hot/Ground going from the outlet to the Spa Panel, but I really meant Hot/Hot/Neutral. It's a 30A dryer outlet from the early 80s, so I assume that is correct.

 

[jCOSbrew]

The purpose of the element switch or contactor is to eliminate power to both phase of the element since the SSR only controls a single phase. The location (before or after SSR) is not critical. Keep in mind that with the element disabled, you might want to operate your PID so connect the PID fuse and power input upstream of the switch.

If you use a contactor instead of the switch, you can use the estop as a panel on/off switch to enable/disable 220v power to the panel by controlling the contactor coil. You currently have the estop setup to trip the GFCI which should only be used for a real emergency.

 

[BadNewsBrewery]

The swithc AFTER the SSR would handle the same amperage as anything else, so if you have a switch you're comfortable with that's rated at 25A and you want to go that way, no issues. You're just breaking the circuit in case the SSR choses to do something you don't want it to do.

There's nothing wrong with having a switch before your PID, I was just asking why - you could achieve the same basic results by unplugging your panel and killing power. You only have one PID / SSR / element so it's not like you're trying to control individual components with the switch. No harm doing it your way though, so keep it if you're happy - your panel!

To do the right / safe thing and have an equipment ground, you need to have a ground line run all the way back to the main panel. The only thing you have in your entire panel that NEEDS 120v (and thus a Neutral) is an LED - the PID can run on 240. So if you only have 3 wires to run, make them Hot / Hot / Ground and swap that LED to a 240v rated one. That may make running your GFCI Spa Panel difficult though, not sure. Someone may be able to chime in, but I'm pretty sure the GFCI uses the neutral. Maybe you can wire it to ground instead? Someone else will have to chime in, or I'm sure it's been discussed on this page in depth.
-Kevin

 

[ComeOnNow]

OK, I changed around the diagram as per some of your suggestion. Let me know if this makes a bit more sense.

 

[jCOSbrew]

My 220v gfci for a spa was connected with hot, hot, and gnd without any neutral connection. This makes since because 3-wire 220v doesn't need neutral.

When I added any outlet for the brewery panel (and abandoned spa wiring) I added neutral through the gfci for 4 wire 220v and 110v in the control panel.

 

[BadNewsBrewery]

So there you have it. Drop the neutral, run pure 240 and have a real ground.