EWC Controls Forum

I have been called in to service a home which has this system installed (BMPlus 3000 with 3 zones. One on each of the 4 systems in a 14ton total setup. Each system also has humidification system(Honeywell model which is independant of air handler fan control) installed as well. In order to properly teach the home owner and make them comfortable with the benefits. I have identified the components but need help on how to identify if the OAS is installed and where it may be in the home. I know there is a status light which should indicate its operation. Any other advice about this would help me. Are/is there some literature that could explain the sequence a little more actual than the tech bulletin. The testing info on page 9 is a little confusing. Never saw these setups in school other than at trade shows.so I have been tracing wiring but their is quite a bit. One of the questions is concerning if more than one thermostat can control the zones in one system and how would that set up look connection wise?
Thanks

To identify if an OAS is installed, Dip Switch 5 should be to the left (OFF) and there should be wires in the OAS terminals on the upper right corner of the control panel. As far as the actual location of the OAS, it is most likely near the outdoor unit. It should be inside of a small 2x2 white enclosure.

Eric

Thx for the reply. Now according to the tech bulletin(from Oct 2004) on page 4 that a separate transformer is required. The "note" says..."the BMP supplies power to all connected modules.
1.Does this mean that one independent transformer can be used for multiple modules? The note goes on th say"...no need to power up modules separately. This would make me think that the answer to Q1 is yes but what if the units are so far away that runs that long were cost and structurally prohibitive. Then would not seperate transformers be the answer. (for lack of a better decscription the units are on the 4 corners of a 10k sq foot box)
The note goes on to say"...improve design and reduces the possibility of polarity reversal"
2. What would that look as far as the wiring connections go? These units are wired up with relays and don't have a seperate transformer.
3. Is there a protocol that would call for using relays (I assume that since the TB is dated 2004 that the installation was 2004.
Now I actually got an opportunity to talk with the previous owner and he indicated that "... he had been told his units were wired in "reverse polarity". He also stated that he has had incidence of 2 of his 4 units just stop working and after a total shut down they start working again. Now doesn't this sound unusual and thus by Q2. I want to know what to look for and should the "seperate power supply issue be addressed because they are functioning however as indicated there are some problems.
4. Based on "Power solutions chart on page 9 there is added current draw with this system thus the need for seperate power supply. There have been incidents of humidity damage...maybe the damper aren't operating properly.
5.Now if there needs to be a seperate transformer would it need to have its own circuit from the breaker box with disconnect or could it tie inwith the line power to each unit and maybe increase the disconnect rating?

I was always taught that any system should not be made just to work but to work the way it was intended. and I would appreciate your assistance in getting this right

Based on the questions you are asking, I am assuming you are having issues with some dampers, is this correct? What exactly is the problem you are experiencing? If possible, I would like to talk to you to discuss your application in greater detail, please contact me at the number and hours listed below.

Eric

Well 2-3 issues are involved.
Issue 1. As reported from previous owner ..."I sent a video of my status lights (don't know who he sent them to" and he ws told he had a "reverse polarity" issue. To which I asked what did your installers do about that. His response..."nothing...and intermittently two of my units will just stop working" One of then "froze up"(This seems to be a combination of low air flow and refrigerant based on service nees and operating pressures of this particular unit. This unit is one of the ones which suffers from "reverse polarity".
Issue 2. The installation itself is inconsistent with what the previous installers are attempting to control. Neither has a seperate power supply. All are running off the furnace power and being ran through a relay set up. I am at the point of comparing the "correct" setup to the "reverse polarity" setup. They seem to have done what EWCcautioned not to do which was try to control too many system components(There are humidifiers and dehumidifiers on one and humidifiers on all units.
Issue 3. One area of home suffered from condensation on the walls and this was attributed to "curtains blocking the registers but this is also the unit I found a disconnected zone moter wiring. Have not had a chance to test if that motor worked and then hook the wiring up and test . I believe previous owner had issues with the dampers not opening properly because one comment was "I would get whole sides of the house that we could not regulate"
So somethings to ponder as we get in touch with one another...I will call you Eric
Thanks

I look forward to your phone call.

Eric

Hello sports fans...Since Packers beat the Falcons I guess we lost to the best team...makes me feel better about it. On to the HVAC.
Should the thermostat in the part of the structure where the zones are be connected on right side of control module indicated by. Then each zone motor will be wired into the appropriate 5 connection designated Zone1...z2...z3?

Would running the module off furnace RC instead of providing seperate power input be detrimental to load handling of the components...i.e. make the damper motors work less than required?

Previous installer uses fan control relays to control humidifier on 3 units and on one unit to control a humidifier(Honeywell 420A Steam Power models) and a dehumidifier. On one which owner was told he had "reverse polarity" the R wire is connected to the relay coil at terminal 2, C connects to terminal 3 and the humidifier is connected to terminal 1 and and then R is connected to humidifier. This may be the source of "reverse polarity"? Make any sense. My question to the owner was why did you never do anything about that?
On unit without any problems or indications of "reverse polarity...has never "shut down" the fan control has R to terminal 3 and terminal 1 has green wire that goes to humidifier and then back to terminal 5(parallel). I am not sure these things even work this way. The unit is heating but that may be all. Need to test. Can't get to phone just yet but any thoughts in meantime will help?

The Zone 1 motor will correspond to the Zone 1 T'stat, Zone 2 Motor to Zone 2 T'stat and so on.

It is highly recommended to use a separate transformer to power the zone system.

Unfortunately, I cannot offer much insight as to the humidifier wiring and relays. What I can say is when using AC voltage to energize a electro-mechanical coil, polarity does not matter.