EWC-ST-2D

[jnewcomer27]

I have control module EWC-ST-2D.

First of all, I can't find any documentation on it. The closest I can find is for the EWC-ST-2E (and -3E). Are there any differences between the -2D and the -2E?

Secondly, the Zone 2 t-stat doesn't appear to be doing anything regardless of what it is set at. In particular, if it is calling for heat while Zone 1 t-stat is not calling, no heat will produce. I checked the Zone 2 t-stat contacts for voltage (according to the -2E documentation), and I get 0V across all contacts when the Zone 1 t-stat is not calling, even between C and R. Shouldn't I at least get 24V between C and R on Zone 2?

The Zone 1 t-stat is a Hunter 44360, which does everything it's supposed to with heat, A/C, and even manually switching on the fan. Is there a jumper connection I need to make? Would it do any damage to run a jumper from Zone 1 t-stat R1 to Zone 2 t-stat R?

Thanks,

John

[Pcyrana]

In regards to your situation, no the D and E series of panels are one in the same.
You should get voltage from C to R on zone 2 IF you have voltage from C to B on zone 1.
Make sure you have voltage there first.
The Hunter thermostat you have on zone one seems like it would be compatible although I cant confirm this because we have not actually tested it here in the lab.
There should be no jumpers on the board.
You wouldn't necessarily damage the board by putting that jumper in place but it would not operate as it was intended to.
If the zone one thermostat is wired correctly there will be no need for the jumper.

[jnewcomer27]

Ok, upon further investigation, the Hunter 44360 won't work as a Zone 1 master with the -2D. What I have found is that the B should read 24V, but only as a return feed from the t-stat (whereas the R1 is feeding 24V to the t-stat). I went ahead and ordered a Honeywell TH4110D, but if I wanted to stick with what I have, I could put a jumper between R1 and B to energize R on Zone 2.

Theoretically, if the t-stat on Zone 1 is in the OFF position (not heat or A/C), then neither B or O would be energized at 24V, which would shut off R to the Zone 2 t-stat. The Hunter 44360 doesn't have a separate terminal to connected to B or O to keep it at 24V while the t-stat itself is not calling, rendering the Zone 2 t-stat ineffective (without a manual jumper from R1 to B for heat or R1 to O for A/C).

Thanks.

[jnewcomer27]

Update - I ordered, received, and installed a Honeywell TH4110D, and all works well. It has a separate terminal for W and O ("heat calling" and "heat system selection" respectively), which the Hunter 44360 doesn't have (but has a terminal that combines W and O). If I wanted to stick with the Hunter as a Zone 1 master, I could have connected a jumper between R1 and O, then switch it to R1 and B for A/C in the summer. However, the Honeywell TH4110D was only $30 + shipping, and is worth it. Both the Hunter and the Honeywell are 5/2 programmable with 4 cycles for all 7 days, and a temporary override that reverts to the program at the next cycle.

Now all that's left for me to do is to replace one of the MA-5P servo motors so that I can have both dampers working. Darn thing is back-ordered!