Help wiring relay for SWG control

[BC in the Bay]

So I finally got my salt cell installed and decided to go with a current sensing relay to drive the power to it since I just put in a VS pump as well. Here is the relay that I purchased:

Macromatic CAH05A1BC 0.5-5A, 240V, 0.5-50 Sec, Current Sensing Relay


I'm hoping that someone can help me to sort out how to wire this correctly. Here's what I've done so far...

• I ran the three wires running to the pump (240 - hot, hot & ground) through the loop at the top of the relay.
• I attached the two hot lines (again 240 hot, and hot) from the electrical panel that would run to the SWG to the #1 and #2 pins on the relay.
• I ran wires from the SWG back into the panel that houses the relay, but I did not connect them yet.

I turned on the pump and the breaker that feeds into the relay. I tested pins 3, 4, and 5 with the relay in both "fault" and non fault mode (this particular relay has a switch to go back and forth between over and under current) and I'm not getting 120 on any of them under either scenario (fault or not). I am getting 120 on both of the "hot" wires that are plugged into pins 1 & 2 though.

I assumed that the relay would transfer power from pins 1 & 2 to either 3, 4 or 5 when the relay was in one mode or the other, but that doesn't seem to be the case. I'm only getting between .5 and 1.5v on those three pins. Clearly I'm missing something here. Are there any electricians in the house that can edumicate me on what I'm screwing up here?

(I think I've attached the manual for the relay here too, but I'm not sure if that worked.)

Thanks in advance!

 

[Jimrahbe]

BC,

Well, I don't read the schematic the same way you do...

It appears to me that the 240 volts applied to pins 1 and 2 does nothing but power the unit, and is not connected in any way to pins 3, 4 or 5.

Pin 3 is the common input pin to the relay and when the relay is not energized, pin 3 will be connected to pin 5.. When the relay is energized pin 3 is connected to pin 4.

To use this unit your SWCG should be powered by 120 VAC. This 120 VAC should be connected to pin 3. You could use the relay to interrupt just one leg of 220 volts, but that is never a good idea.

I would also only run one of the hot wires going to the pump through the core, and let the other wires bypass the core.

You may have to wrap the one hot lead going through the core in and out of the core several time to get enough sensitivity for it to work.

Keep in mind that is my reading of the instructions.. I have never seen this particular unit.

Thanks,

Jim R.

 

[BC in the Bay]

Well, bollocks....that makes sense with the 5 pins.

Ok, so this relay isn't going to work with a 2 pole power supply. Has anyone used one that will work for a 240v supply to the SWG? Does the SWG not use enough power to worry about keeping on 240 vs knocking it down to 120?

Thank you for explaining that, Jim.

 

[Jimrahbe]

BC,

I'm not up on your particular SWCG, but most them can be powered by 120 or 220 by changing jumpers or input wires inside the control unit. Should be in the manual for the SWCG.

The SWCG will function the same with whatever power you choice..

Thanks,

Jim R.

 

[JoeGolan]

You could also just add a double pole 2nd relay
120 Volt coil to be powered off your 1st relay's contacts
240V interrupted by the contacts

 

[Jimrahbe]

You could also just add a double pole 2nd relay
120 Volt coil to be powered off your 1st relay's contacts
240V interrupted by the contacts

Joe,

Good idea... I'd want to make sure the current sensing portion of the unit worked first. I admit I have not searched a lot for this info, but so far I have yet to see someone report that it has actually worked for them.

Thanks,

Jim R.

 

[BC in the Bay]

You could also just add a double pole 2nd relay
120 Volt coil to be powered off your 1st relay's contacts
240V interrupted by the contacts

Thanks, Joe - I like this idea. I have this one on order to go this route:

SCHNEIDER ELECTRIC 120VAC, 6-Pin Bottom Flange, Din Rail Enclosed Power Relay92S7A22D-120A - Grainger

Thanks for the help, guys...I'll advise when the final product is up and working.

 

[BC in the Bay]

FWIW - the current sensor does actually work. I rewired a few things to get 120 to the SWCG today. It's all working as planned. The current sensor has a dial to adjust the fault point, so I can actually adjust it to trip above/below a certain percentage of run speed on the VS pump. I did have to separate the three wires and just run one of the hot lines through the sensor, but I didn't end up having to loop any additional passes to get it to work as desired.

It may be a while before I get back to rewire everything to 240 with the additional relay (since it "ain't broke" at the moment), but I'll update when I do.

Thanks again for the help.

 

[Jimrahbe]

BC,

With your permission I would like to condense this thread into a new one showing what you did. I'll give you credit, I just want to be able to provide a link to a working unit.

Let me know,

Thanks,

Jim R.

 

[BC in the Bay]

Hi Jim,

Yes, of course - feel free to reformat anything however you think the information will be most useful. I'm just happy I actually got it working as planned!

 

[JoeGolan]

Thanks, Joe - I like this idea. I have this one on order to go this route:

SCHNEIDER ELECTRIC 120VAC, 6-Pin Bottom Flange, Din Rail Enclosed Power Relay92S7A22D-120A - Grainger

Thanks for the help, guys...I'll advise when the final product is up and working.

Looks like a good choice for the relay, contact rating well exceeds your intended load so it should last a good while.

To make the connection to the relay terminals use a "Sta-con" type INSULATED SLIP-ON CONNECTORS such as seen here

PVC TERMINALS FULLY INSULATED SLIP-ON CONNECTORS - PVC Terminals - Wire Terminals

choose the proper color of connectors to match the wire size of the connecting wires, the chart I pointed out gives you the specs.

You can purchase these at Home Depot or the like..... maybe also an automotive part store will have them too.

 

[CoraDias]

Hi...If you're connecting the limit switches to the DIO ports or the limit switch terminals on a motor controller, then yes, it's signal level wiring. The signal wire is not "constant polarity", but the ground line are. Even though the color code isn't mandatory for signal level, it makes things much easier to identify and understand. We usually use PWM wires in appropriate colors for our limit switches.

pcb assembly

 

[hopkiba]

I have been struggling with how to hook up a planned SWCG to my system that has a VS pump with no external timer. The time solution does not seem fail safe since if the pump were to fault, the SWCG would still run. Your solution seems to be the best. Can you provide pictures of your final set-up? Thanks!

 

[Mrmumbels]

BC,

Well, I don't read the schematic the same way you do...

It appears to me that the 240 volts applied to pins 1 and 2 does nothing but power the unit, and is not connected in any way to pins 3, 4 or 5.

Pin 3 is the common input pin to the relay and when the relay is not energized, pin 3 will be connected to pin 5.. When the relay is energized pin 3 is connected to pin 4.

To use this unit your SWCG should be powered by 120 VAC. This 120 VAC should be connected to pin 3. You could use the relay to interrupt just one leg of 220 volts, but that is never a good idea.

I would also only run one of the hot wires going to the pump through the core, and let the other wires bypass the core.

You may have to wrap the one hot lead going through the core in and out of the core several time to get enough sensitivity for it to work.

Keep in mind that is my reading of the instructions.. I have never seen this particular unit.

Thanks,

Jim R.

How are you to power the relay with a double pole 240v when there's only a single + and - input? Are you allowed to tie the 2 poles together at the +?