High-limit contactor needed?

I was wondering if the high-limit contactor was actually needed? I see in a newer model of the hot tub spa pack I have, they eliminated it and redid the wiring a little. If I can re-wire for that then I might be set.

The second picture is how it is now.
The first picture is of a newer spa pack with the eliminated contactor.

Would this work?

Posted by on 2006-07-25 20:07:30. (6416)

for safety reasons most equip manufacturers have (or have to, in Australia at least) use 2 contactors in series to break the heater power circuit. this is to safeguard against element melt down in the event of a single contactor fusing its contacts putting power to the element when heat is not called for. a second contactor on the pressure switch/thermostat is a back up in the event the fist contactor does fuse. it is assumed the fused contactor will be noticed by a service tech during routine servicing before there is a chance for the 2nd contactor to fuse as well. seen fused contactors on many occasions so don't risk downgrading the safety features of your spa, replace the contactor

Posted by on 2006-07-26 01:44:06. Australia (6422)

Here is the biggest reason why I ask...I have 120v at the heater element even when the heater is off. When it is on I have 240v. Looking at the wiring diagram, this makes sense, but from a high-limit tripping issue/heating issue, this makes no sense. I can see that as long as the spa pack has power, the high-limit contactor has power to it as long as the high-limit sensor isn't tripped. This would then cause the coil to energize and pull the contacts shut, therfore allowing 120v to pass to the heater element and 120v to pass to the heater contactor. The heater contactor would close when the demand for heat is called for thus giving 240v to the heating element. But the element should have 0v when no heat is called for. This would not allow it to overheat and the high-limit to trip. So somehow I need to re-wire it so that there is no power until called for. I can figure that out easily. But if it would be ok to eliminate the extra stuff, and wires, that would make the pack less crowded and more cool.

Would this configuration be ok?

Posted by on 2006-07-26 15:56:57. (6428)