Trane Summit/Tracer/Voyager Question

[jogas]

I've started working on a problem job that has a summit front end (with several CPL programs), webs, and voyager VVT RTU's with bypass dampers. It appears the property links are not right and the system is not running properly. When I arrived on site the 2 main RTU's were switching from 100% heat to 100% cool every 3 minutes with one economizer OA open 100% all the time.
I'm finding choices for say economizer control at local instead of tracer even though there are Tracer binary variables or CPL programs that would control properly.
One RTU was in 100% outside air constantly even though the unit would be in 2 stages DX cooling or 2 stages of gas heat. I found out the changeover signal from that RTU is not working, so I directed the changeover from the RTU next to it to control the first RTU's changeover. Seems to be working.
I've never had to deal with so many levels of programming before.
What is the difference between Tracer and Summit and Local?
I'm trying to get a sense of the levels of programming and how they are supposed to interact thru propery links.
If I haven't worded this properly, it's because I've never had any Tracer or Summit schooling. So excuse my ignorance.
TIA,
jogas

[kwillmech]

Two important screens in the Intellipak editor:

The first one here,
-Unit Control Source: determines if the Intellipak is controlled by Tracer or in Local control. In Local control it will ignore Tracer occupancy requests and will revert to Occupied and what ever keypad setpoints are.
-Heat/Cool Mode: in Local the unit will decide to change over between heating and cooling. In Tracer then you can set to limit for heating or cooling only mode, not auto change over. This selector can be optionally referenced to look at something else (CPL, Binary point, other units, etc).
-On/Off Times: Only used for occupancy, not for compressor or fan delays.

http://img405.imageshack.us/img405/4504/image1ji5.jpg




Second screen,
-Control Source: When set to Local the Intellipak can decide to go in to full economize mode or not. In Tracer Mode it will follow the next option below called Tracer Economizer Request. Example, If Set to Tracer and Disabled then the economizer will only stay at minimum position.
-Economizer Minimum Position: This is the minimum setpoint regardless of Economizer Control Source. If set to Not Used then the Intellipak will use the kepad setpoint.

http://img85.imageshack.us/img85/382/image2lj1.jpg

[controldude]

Sounds like another site where operator/maint guy playing with points they don't understand if I lock them out of these editors I get blamed for holding them hostage, instead you get to come back and charge them for what they screwed up.

[kwillmech]

As long as it is not in warranty they can screw up any thing they please. The more the better and will take me longer to figure out and fix. Could be by the hour, could be by the day.

[jogas]

In this case, the job was put in in 2004 and has never worked right. It appears it was never commissioned properly. We have been called in by the customer to try and get it working right, or they are ready to replace the whole control system.
When I put the Voyager Editor first page in "Tracer" Heat/Cool mode, and the value is off (Occupied Heat) the unit shuts off. When the Tracer Heat/Cool mode value is on, the unit runs in Occupied Cooling mode. I cannot get it to run in Occuppied Heat at all.
There are 2 RTU's M/N YCD330 with a bypass damper AND a VFD (OEM). Each RTU also has 3 control relays added that are controlled by an MP581. As far as I know yet, the first 2 relays are the stage1 heat and "changeover" with coils wired in parallel off one binary output. So the unit is in either heat, or cool, no ventilation. The third relay is for second stage heat (I think). I'm gonna verify wiring Monday.
The system has 3 trunks. Two Comm4 trunks each having a YCD RTU and either 18 or 27 UCM (?)VAV's. The other trunk is a Comm5 having ZN.511's controlling FanCoil Units.
There are also custom CPL programs that look at all the VAV zone temps and decide what mode (heat or cool) the RTU should be in by zone temp deviation from set point. None of the CPL programs were being used. I'm gonna try to link to them as this should be telling the RTU what mode to be in.
Anyways, I'm looking to simplify this system. Can I bring a CPL value(s) into an MP581 program to control the RTU heat/cool mode by binary output? I can write a program easily in Rover to do this.
Any other suggestions would be helpful.
TIA,
jogas

[vbhvac]

Are this voyagers set up as CV or VAV, what is controlling bypass damper and VFD, what kind of heat voyager has modulating or staged, does VAVs have reheat or not? It looks like there is some screwed up logic hiding in MP580. The easiest way will be to take average from VAV boxes put it as a temperature sensor value in the area, and let the area make heat-cool decision for the particular unit. The fact that it was not done tells me that it might be more to it.

[jogas]

Are this voyagers set up as CV or VAV, what is controlling bypass damper and VFD, what kind of heat voyager has modulating or staged, does VAVs have reheat or not? It looks like there is some screwed up logic hiding in MP580. The easiest way will be to take average from VAV boxes put it as a temperature sensor value in the area, and let the area make heat-cool decision for the particular unit. The fact that it was not done tells me that it might be more to it.

Voyagers are CV with bypass (I've never seen the VFD at anything other than 100%. 2 stage gas heat. No VAV reheat. There is a CPL that crunches min, max, and avg. zone temp. I'll check if the temp sensor is referencing the proper CPL saved value.
Again, when the control mode is in Tracer and is set to heat, the RTU shuts down. Any thoughts?
jogas

[vbhvac]

What is controlling bypass? Also when you say in heat unut shuts down - does this mean unit is going unoccupied, or unit status is occupied heat and the fan is not running, or unit is trying to start up and going off? I do not think the problem voyager setup through rover, you still can connect to it if it has reliatel. Also on the voyger commercial if you switch it from cool to heat it takes about 5-7 min. during which unit is going to min speed on the fan before switching over.

[jogas]

What is controlling bypass? Also when you say in heat unut shuts down - does this mean unit is going unoccupied, or unit status is occupied heat and the fan is not running, or unit is trying to start up and going off? I do not think the problem voyager setup through rover, you still can connect to it if it has reliatel. Also on the voyger commercial if you switch it from cool to heat it takes about 5-7 min. during which unit is going to min speed on the fan before switching over.

There's a setpoint of 1.5" W.C with a .2" W.c. differential in one of the editors, maybe voyager, I can't remember. I''ll check that and for the "5-7 minute mode switching delay" tomorrow. Thanks. BTW, the static sensor pickup is in the RTU, not 2/3 way down the duct. Does that make a difference on this system?
I went thru the heating logic today and straightened some things out.
I also added some logic today at the MP581 level that controls an economizer enable local variable and a compressor enable local variable that I referenced to the voyager editor compressor enable property and the economizer enable property. For the first time ever, the economizer is disabled, the compressors are enabled at 60 degrees and above OAT. And vice versa below 60 degree OAT. I manipulated the 60 degree set point and watched it all work properly just before I left the site today....pretty cool when it works right.
I had a problem today with a local read variable that can not get the value from Summit. I had to global reference it to get it to read properly at the MP580 level. Any ideas?
Again, thanks to all for the help.
jogas

[vbhvac]

Voyager editor will most likely control VFD, unless VFD is set up on 100% and Voyager output is wired to bypass damper which you will need to find to get full picture. Also the local variable is the one being send from controller to the summit, like for example in your case economizer enabled, when summit variable send from summit to controller - occupied for example. Try to check what is the status of the unit when in heat it shuts down.

[jogas]

vbhvac,
I never realized that local variables communicate to summit, and summit variables communicate to the controller. It makes sense now that you said it. Thanks.
I also found yesterday that there is a "changeover relay" in parallel with the first stage heat relay that interrupts the UCM cooling output to the compressor contactor(s). I've got UCM control info on the way so I can see what they did.
I'm thinking instead of trying to control the compressors on the UCM output, I should have relays controlling the compressor disable for each compressor. Voyager status shows these as disabled now. Should be some wiring terminals to accomplish this? I could even disable the second compressor below a certain OAT. Right now, both compressors bang on at the same time, there is no staging. Because of the 5 minute min on/off, I've seen 39 degree discharge air temps...WOW. There is/was always LPC/Freezestat diagnostics that would lock out both compressors every morning. I can see why now. There has already been a freezestat that was replaced (probably wore out).
I'm going to create 2 BOP in the MP580 today and see if I can get this DX cooling running right.
And when I'm done with this RTU, there's another carbon copy sitting right next to it that's doing the exact same thing.
jogas

[vbhvac]

What dazzles me is the fact that it is possible to achieve everything you are describing through Voyager editor - mechanical cooling disabled and number of compressors enabled, so i really do not understand the purpose of changeover relay. It looks for me that the system had some problems and instead of addressing it somebody, and I’m not talking about you Jogas, made it worse by adding questionable controls.
Also it might not be enough just to switch heat-cool from tracer if the unit is CV, you need to bump up set points, on another side if the unit in editor has pressure SP it means that it is set up as a VAV and in this case you will need to bump up day time warm up settings, because VAV unit is always cool, only when the temperature drops below DWU SP unit switches to CV, ramping VFD speed to 100%, sending a signal to drive VAVs open. This is a sequence for stage heat. It can be different for modulating heat.
What i would try to do remember existing configuration, and set it in normal way - as I described - and then you might be able to see what actual problem is.

[jogas]

vbhvac,
I found out today that the cooling lockout relay's one set of contacts is wired to both compressor disable terminals on the Voyager. I left it in for now.
I did give the voyager heat/cool mode a heat signal, the rtu stayed in occupied cool, but shut down. When I looked at the fan after 5 minutes, it was starting to ramp back up, but still showed an occupied cool status. The heat came on during this time and tripped on a failure. Both stages of heat are removed from the UCM relays and are controlled by the MP581's BOP 1 & 2 that I found out today was added by the last contractor. I added a permissive in the MP581 for now that won't allow the first stage heat to come on 'til the fan is greater than 50%.
I was able to link a binary to the compressor tracer enable, and an analog output to the compressor stages that seemed to work.
I also have a CPL saved value that provides number of zones calling that I added into the cooling permissive logic.
Is there a Document that fully explains how Trane would like to see this system work? I'd like to do this right, and I will if I can get a good sequence of operation.
And also how to link analog and binary values between summit and the MP581? When I do this it sometimes works and sometimes doesn't.
jogas

[vbhvac]

My guess - it was some kind of CCP retrofit, which did not work too good.
You will need to find why the unit is failing in heat - now it sounds like mechenical problem, also you will need to find what is controlling bypass damper - I don't see anything from what you told that can be controoling this damper. And if this damper is not controlled properly unit can go on Hi limit in heat.
After I would try to remove all overrides binary and software and feed average temperature to voyager space temperature, DWU temperature and MWU temperature, and put heat/cool as a local instead of tracer, but you will need to find what is controlling bypass damper before doing it.