Hi,
Can anyone share a simple diagram of the wiring of a 3 phase 480vac contactor that switches a 3 phase heating element in wye, which is being controlled via a loop from the main contactors L1 and L3, powering the aquastat andhigh limit sensors which loops back to A1 and tying it in with A2 jumpered to L3? Hope that makes sense (?) I want to print out a pocket diagram of the above layout to help visualize this simple circuit in the field.

 

I have seen in several occasions that contactor manufacturers show typical wiring schematics. In said schematic, the low limit sensor would be shown as a NO switch, the upper limit as a NC switch. This is a very, very common contactor use.

This is one of the instances where AI can actually help you. Instead of you searching random contactor datasheets, you can ask AI to do it for you. But please do share whatever AI provides you with here, to ensure it didn't gave you some AI slop.

 

Post a diagram, which, BTW you should alwayts sketch out when doing anything like this.
What is your 3ph voltage?
If the coil (A2) is connected to 480v L3, what is the coil voltage??
A sketch will get you help.

 

Thanks the voltage is 480vac and I assume the contactor coil is rated for that as well. Aquastat and highlimits rated for 600v which is common. I will ask AI again. I did try AI and got back broken links both times. Which leads to the next question, Have folks in the eletrical field gravitated toward a best/useful AI source?
Thanks for the input.

 

Typically contactor coils max out at 240v , in N.A. most are 120vac.
The tendency now for industrial use is 24vdc .

 

heater power?

 

Thanks the voltage is 480vac and I assume the contactor coil is rated for that as well.

Why would you assume the coil being 480v ?
Particularly if the coil is controlled by lower level moitoring devices.

 

Why would you assume the coil being 480v ?
Particularly if the coil is controlled by lower level moitoring devices.

Because the control circuit get's it's power jumpered from L1, through the control circuit loop/sensors and back to A1. A2 is jumpered to L3 so I assumed combining two legs produces 480v in the same way measuring voltage across L1 and L3 would produce 480v. THere is no low voltage or secondary control circuit power. It is all fed from the 3 mains coming into the Contactor.

 

heater power?

Yes, this circuit is for energizing a single 3 phase 480 heater element in a hotwater storage tank. The element is wired in a wye or star configuration. The control circuit is using the same power source (two legs of it jumpered from L1 and L3 power the controls (aquastat/highlimit) via a jumper off L1 through the control loop back to A1 on the other side of the coil, A2 is jumpered to L3 completing the control circuit.

 

More info (schematic?) is needed in regard to how the temp control etc, works?
If you need a schematic, quite a bit more info is needed, any and all sensors, switches etc??
Wired star or delta will depend on heater ratings ?

 

the schematic is simple provided that details are shared.

so far we know:
you have 3-phase heater 480V, no current or power rating of the heater is stated. no part number or datasheet is linked.
you have one or more thermostats, no part numbers or specs provided.
control method is not provided, probably just selector switch,
possibly indicator lights to show that heater is on, and at temperature.

 

High voltage controls wiring KILLS PEOPLE VERY DEAD!!!! The 480/ 3 phase is 277 volts above neutral, aside from being 480 volts between phases. A small controls transformer is the way to go! Seeing one poor fool get zapped and fall off a ladder dead is quite enough. Certainly 120 vac also is a real shock hazard,but not as deadly.