EWC Controls Forum

Could you please tell me how to adjust the BMPlus 2000 so that the heat pump doesn't continually cycle? I can hear the heat pump kick off, the blowers expel the rest of the heated air through the ducts, the fans to quit, then IMMEDIATELY the heat pump comes back on, and the fans start again. Is there some delay I can institute? Is there some temperature change I can adjust (say a degree or 2 fluctuation) to keep this immediate recycling from occurring? Is this normal? Is this creating a problem for the heat pump?

Thank you for your help.

Gary,

When the system is operating normally what LED's are lit on the panel and when the cycling occurs how do the LED's change?

Eric

Eric,

Thanks for getting back to me on both posts. The chipset on my panel is "EWC Controls, Inc BMPlus2000, vers 1.2". The lights are from top to bottom, z2, z1, w2, y, w1b, g with a "status" light to the right of these. The status light blicks 3 times fast then on for a second continuously. When there are no calls to the system, the w1b light is on along with the z1 and z2. When the system gets a call, the g, w1b, y, and appropriate z1/z2/both are lite. When the outside unit kicks off, the y light goes out. When the fans quit running, the g light goes out, and just before this happens, the z2 light (if z1 was the original call) comes on so it too seems to get the circulated air for a moment.

So when it is cold, just after the system "shuts down" and goes back to w1b, z1, z2 lite, it immediately kicks back into g, w1b, y, z1. This is the cycle that concerns me as it only seems to "catch up" long enough to circulate air, then comes right back on again. There is never a few minutes delay for the temperature to change before it kicks back on. Is there something wrong or are the tolerances on temperature overshoot and call so close that when it is cold, it never really can rest. As the temperature outside warms up, these "rests" do start to occur and for longer intervals.

The "dials" of w2 timer, heating limit, cooling limit all have the arrows pointing straight up. EM Heat switch is "off", fan sel switch is g/hp, the upper right dip switches are top to bottom: left, right, right, left.

Does this help any? Thanks again!

Gary,

Are you using a Supply air sensor on this system? If so try disconnecting it temporarily and observe the system operation. Does it operate differently or the same?

Eric

there is no supply air sensor. The resistor is still in place, and no wires going into that block at all.

Maybe it will also be a mute point as I'm trying to replace the current thermostats with heat pump programmable ones. Since you said most heat pump programmable thermostats should work, I went with the LUXPRO PSP722E 7 day programmable system. It worked well on the separate downstairs heatpump that is independent of the BMPlus 2000. This is a 24v system with great flexibility. I don't know if you've heard of it being used before but looking for typing this unit on google brings up the install/use manual.

I changed out the Honeywell simple thermostat I described earlier. There were only 4 wires between the BMPlus2000 and the thermostat (G(fan relay), R(transformer), W(aux heat relay), Y(compressor relay)). I took those wires and put them onto the PSP as it states (G-G, R-RH/RC (jumpered together), Y-Y1, W-W1 (I did not add a jumper to E for emergency heat). Then programmed the thermostat and I could get NO heat. The fan would come on some, the upstairs thermostat would still work fine, but nothing from the new programmable one.

After doublechecking the wiring (was fine), I went back to the BMPlus2000 and read the manual again. You can see from the earlier posting that the dip switches seemed to be set for a HC thermostat for zone 1 and not a HP one. Following the manual, I reset the dipswitches to that 1 was now HP, 2 stayed at HP, 3 I changed from B to O, and 4 went to OFF for the EM. It then began to work a LITTLE bit but but I couldn't get the W1/B led to come on for zone 1 though it worked fine with zone 2. Also, it only seemed to work even then when the house temperature was about SEVEN DEGREES below the setpoint temperature. Suggestions on how to wire this thermostat and the right settings for the BMPlus2000 to have them work together so I can start using setbacks?

Thank you so much for any help you can provide!

Gary

Gary,

Heatpump thermostats will not work properly with that panel. I stated Heat/cool thermostats will. This could be the cause of the issues you are having.

Eric

Eric,

Thank you for the clarification but I'm confused since the instruction manual for this BMPlus2000 says that a heatpump thermostat will work at least for zone 1 and gives instructions for how to wire it up. I read over those again, and when I added the emergency heat wire from the zone 1 thermostat block on the BMPlus2000 to the E terminal on the thermostat, and the common wire (C) in the same way, and moved the W1/B/O zone 1 block wire from the "W1" terminal on the thermostat to the "O" terminal, and reset the dip switches as in the manual to HP for thermostat type, HP for heat/cool equipment type, O for O/B relay type, and EM SW to NO, it all worked PERFECTLY!!!

So given that, I have 2 questions. Can I use the same thermostat for the zone 2 thermostat even though there is no W1/B/O connection on the zone 2 block of the BMPlus2000? Again, what I'm after is the ability to do setbacks based on TIME.

The second question concerns the aux heat/emergency heat/automatic defrost cycle for the heat pump. It appears that all those are controlled by the BMPlus2000? At least the first 2 (aux/em) appear to be through the W2/E terminal block on the lower left of the BMPlus2000 panel and the presence of the W2 potentiometer (which I set to it's max - 35 min). The "time of day" pricing at my electric company is based on MAX KW in any 15 min period during "high peak". This is a killer with the ADDED charge to the bill being $10/KW (in exchange for about 60% of the standard hourly rate for the total KWH in the month). I have a TED (the energy detective) and can monitor electric load/usage. When the aux/em heaters come on, my power changes from about 5KW in heat pump mode to 17KW. I want to AVOID this and am willing to have some discomfort in exchange. Can I DISCONNECT the W2/E wire to no ill effect other than no strip heaters? Can I run this wire to a toggle switch that I can control if it gets REALLY cold (live in mid SC) so I can get back up heat? If I disconnect/switch this wire, will it have ANY effect on the "defrost cycle" of the heatpump? I don't want to cause any equipment damage. (how does the BMPlus2000 handle defrost? is it inherent to the heatpump unit and not under the control of the board or the thermostat?)

Thanks again for your help!

Gary

You can only use the Heatpump thermostat on zone 1. Use a programable Heat/Cool thermostat (non-heatpump) for all other zones.

As for the W2/E output, you can control that through a switch if that is what you desire. Doing so should have no effect on the defrost cycle as long as the defrost output from the heatpump is connected directly to the auxiliary heat terminal within the airhandler. The BMPlus2000 has not control or interaction with defrost.

Eric