Converting old Balboa TO 120v

[tfrasca]

I just got an old Caldera hot tub, with a Balboa WH-CAT75 heater assembly. Based on the sticker, it was made in 2000. It's currently set up for 240v, but I think I'd rather run it on 120v because my house's electric situation is slightly complicated.

Following the wiring diagram on the front panel of the unit, setting it up for 120v is just a matter of moving a jumper to the 20 amp setting, rather than 50 amps, and making a jumper wire between two spade connectors on the board. Easy enough. What's not clear is how I wire up the main power wire to the terminal block on the board. Right now, it uses awg 6 wire with 2 hots, a neutral, and a ground. All the 120v hot tub cords I've seen use 3 wires, of course. My question is how do I wire the 3-wire cord to the terminal block?

Has anyone dealt with this on an older hut tub heater before?

Thanks for any input.

[CanadianSpaTech]

You will need to post photos of the circuit board and the schematic on the inside cover.

[tfrasca]

Good point. Here's the board. You can see the main power terminal block on the left (4-wire 240v wiring removed), but it's hard to make out much beyond that without seeing it in person. The small jumper for 20/50 amps is in the upper right, and the jumper wire needed for the heater to operate on 120v would go between the J4 and J15 spade connectors. It looks like the previous owner had the heater running on 240v, but everything else was still on 120v.



Here's the schematic that goes with it:

[cranbiz]

Black to black, white to white and ground to ground. Red terminal stays empty.

You can see that the white white goes to the J5 etc. set of terminals (110v) and the red terminal goes to the J18 etc terminals (220v)

Looks like you have the rest of the wires set up correctly.

[tfrasca]

That was my inclination, but the jumper from the white set of terminals to the red set for the heater threw me off. But I guess the circuit for the heater uses the red set, and the jumper wire pulls power from the white set in the absence of the red wire.

Thanks!

[tfrasca]

Well, I got this thing running on 120v, but not without some issues.

Again, this is an old Balboa 2000 Value Series spa pack, which I've recently converted from 240 to 120, following the wiring diagram on the back of the cover panel.

This is a bit of a journey, so please bear with me.

To convert the board to 120, I removed the four 240 wires from the main power terminal block. I then hooked up my three wire 120 hot tub plug w/ GFCI. The red hot terminal was left empty based on the advice above.

Then, according to the diagram, I run a jumper wire between terminals J4 and J15. Lastly, I moved jumper J23 from 50a to 20a. This configuration ran everything perfectly, except the heater. No voltage was present at the copper tabs on the heater tube.

Upon further inspection, I noticed that the jumper between K1 and K4 relays (high limit and heater) was the reverse of what the wiring diagram showed. I switched the wire and now have voltage at the heater. The problem is that the heater will not turn off, and eventually triggers an OH error code and shuts down.

The pump seems to be flowing enough, and I even tried running it with no filter to rule that out. Both slice valves are fully open.

Any suggestions on what to try next? I'm sure it has something to do with either the high limit/heater relays or the jumper wire between the two. It seems weird that it was connected incorrectly, based on the diagram, but presumably worked well for years on 240v.

[tfrasca]

Hi again. Just wanted to update this in case anyone has any advice. I'm still dealing with overheating on this old Catalina Spa/Balboa Value 2000 pack.

If I set the temp to say, 100, it'll heat all the way to 110ish then throw the OH code. If I let it get up to 100, then turn the temp down, it'll stop heating. This tells me that the thermostat is working, right?