Varitrane VPEF heat troubles

I have a varitrave vpef vav box with a ucm4.2 board. This is a 460v 3 phase unit. On a call for heat the blower will come on, make the air switch and and go to the contactor that beings on the heat strips. This is a single stage unit. The orange wire(com/grnd) is not making a ground so the contactor won't pull in. The back of the ucm board looks good, no burnt connections. I havn't had a ucm board go bad on me yet but could this be? I can jumper the orange to a ground and contactor pulls in and all is well till it's suppose to satisfy lol. Is there a way to test the ucm board?Attachment 335591Attachment 335601

Does the common wire go thru any switches? Or does it come straight from common on board to contactor? I have had a wire break that still read voltage thru it but, wouldn't pull in a relay because no amperage could go thru it.

The common goes strait from board to contactor. Check wire continuity and a new temp wire from board to contactor. So im thinking it's internal to the board.

The UCM breaks the common. Can you see the status of the heat output through software? Are you meeting the min heat flow setpoint?

I will check that tomorrow. It is connected to tracer software, set to thumb wheel control. I have not verified actual cfm output but i do know blower is running wide open and nada.

On another note. What do the dip switches control on the ucm board?

Quote:

---

Originally Posted by hvac69

The UCM breaks the common. Can you see the status of the heat output through software? Are you meeting the min heat flow setpoint?

---

:ditto:

Quote:

---

Originally Posted by Crazecodyk

On another note. What do the dip switches control on the ucm board?

---

Addressing

The dip switches are for software addressing 1 through 64 and E-ware address 65 through 127

So if the dips 5&6 are in the on position that should be the tracer address for that unit?

Ok. After looking at it today. Was able to bring it on via tracer system. I don't think the vav has been fully set up yet my the trane guys. So i've got it in manual mode till the rest of the construction finishes.

The dip switches are a little tough to decipher, but here is a quick explanation.
Each switch represents a value in the binary number system such as 1, 2, 4, 8, 16, 32, 64, and 128.

Note: VAV UCM 4.2 only use 6 Switches
Summing the switches that are in the on position determines the address.
For example 1, 8, 32 are in the ON position = Address 41
NOTE: This is the actual UCM address and will not always be the actual Tracer address listed for Hardware.
This will be dependent on Comm such as Comm 3.

You are using comm 4 most likely but will need to check.

Trane Everyware Software:
Must Add 64 to the base total:

Example: 53 + 64 = 117
or: 1+0+4+0+16+32+64 = 117
or 1+4+16+32+64 =117
or: 53 UCM Address + 64 E-ware address = 117

As for the comm wire I see that they are on TB2-5 and TB2-6. I normally connect this to TB2-1 and TB2-2 and the daisy chain to TB2-3 and TB2-4. How ever there are others who connect the daisy chain to TB2-1 and TB2-2 as well. There is more than one way.

Your connection may work but needs to be verified that it is correct. As for the shield it must be connected with one another and tapped back so as not to touch any ground or the metal cabinet.

Have you set up the VAV's and verified that they are configured correctly.

What do you mean that you have it in the manual mode? Are you saying that you have overridden functions?

Hope this helps

________________________________________
Trouble shooting is not part of the repair........understand the symptoms and you will find a solution.

I've installed theses VAVs in the past but never set one up to run off tracer. I would like to learn more of that. I have books that i am slowly reading through to self teach me.
I was able to get into the tracer system ,click on the unit graphic, and overide the unit to come on(still unclear how i did this) they are haveing alot of communication issues with several of their units on several floors. Once all the construction is over, all the control guys are going to have to add all the new vavs to the system as well as troubleshoot the old ones as well. Wish i knew more about it. Will get there though

Books are good to read but will not be helpful to you, unless they are application specific and in this case ONLY discuss Tracer Summit. I suggest when learning this system you stick to the original installation operation manuals, which include the following:

Hardware and software Installation
System Programming
Daily Operations


VAV's are one thing but the building set up is a whole other animal.

The first thing is to identify what you are working with. What version of Tracer Summit you are using. How many BCU's and other hardware there is depending on how large the system is. Identify the comm links such as comm 3, 4, and 5 which will depend on the type of equipment that is connected to each BCU.

You need to identify all AREAS and the list of MEMBERS. Think of this as individual spaces with a combination of mixed zones such as common areas which contain entrance, lobby, hallway and exit corridors as an example. You will have business office space, general office's etc. These Area's can be divided in may ways such as East and West wing and subdivided by tenants, or floor levels in the case of a multi-story building. It is very important not to confuse AREA with individual zone's or sub divided space's as there is nothing similar about them. It is the AREA which will control the VAS- Variable Air System along with it's MEMBERS such as VAV boxes, package units, air handling equipment, etc.

This is important to know because the AREA will be controlled by a time of day schedule that controls start and stop function of all the equipment. These separate AREA's will be controlled independently of all other AREA's for example a different schedule all together and start stop times as well as the capability of adding an EXCLUSION date for holiday's or vacation or what ever you wish.

As you work on the VAV's you should map them out as you go. Listing there exclusive UCM address as they cannot be the same. This will be helpful as you commission the equipment and you will be able to identify each UCM no matter if the description is different.

In set up you can change there description but, if this system has graphics you will not be able to recognize or click on them as the NODE located in the tree will have changed. This is somewhat difficult if you have not done this before and for now DO NOT change there description. If you do it will be necessary to update the graphic such as Static information and OBJECT information.

The truth is that this does not even cover the basics, as there is so much more to cover. I will dig up a past post and resend it to you if you want a better description.

___________________________________________
Trouble shooting is not part of the repair......understand the symptoms and you will find a solution.

That would be great!!! The book i have is the daily operations manual. I hope next year after my business picks up i can go to classes on these. This is a great customer and we have a great relationship. I am going to learn this at least so i can troubleshoot the units that are there.

AREA: This is where you will set up temperatures and individual set points related to individual areas. You can set AREAS to control any group independently from other AREAS such as office space, floors, common areas, warehouse, etc. etc. The area itself is unique as your space can be subdivided for individual temperature control, and also has the capability to have different start and stop times. This is helpful when as an example you have subdivided areas and or have different tenants on individual floors or areas which require different schedules such as weekend use or holidays or if necessary exclusion dates can be created. This information is available for your use at the bottom of the screen located in the help menu. You should familiarize yourself with the help screens which are available at all windows. It is very helpful to have more than one AREA so that individual times can be established.

VAS: Variable air volume air systems (VAS) is made up of VAV boxes, air handling equipment which supplies hot or cold air to boxes.
In addition ventilation equipment such as Outside air VAV boxes, make up air fans and building exhaust fans. VAS works with AREA CONTROL where it receives start and stop status through the TIME of DAY SCHEDULING. Remember it is the AREA which helps manage the VAS to control operation of all the VAV boxes and air moving equipment.

VAV boxes are listed as MEMBERS which are related to the VAS and controlled by the AREA which it serves.
This is where you set up the votes for your VAS and when changes are made you will need to reset the votes. This needs to be checked and if not maintained will give you an erratic control. Such as in the case where a remodel has occurred and originally you had 10 VAV boxes but you now actually have only 8. This will alter your votes.

CPL: Custom Program Language allows for custom programs and calculation which cannot be done in other applications in Tracer summit. This is somewhat difficult to do and changes to CPL are not recommended at first. In order to familiarize yourself you may want to open CPL and print out its program. When exiting do not save changes. You should be able to review the list of VAV's and UCM's which will be responsible for the temperature reference. This is accessible and listed in the CPL editor. You will need to locate the VAV's in CPL and verify they actually exist as well as positioned where there temperatures are accurate.

As far as the set up of the Air handling system you should set the static pressure to 1.5" W.C. which is the design of your VAV box and will give you the best accuracy and a good starting point for the commissioning of your system. This VAV box is capable of working with less static and much more up to 3" but should not be necessary for any setting other than 1.5" especially when balancing. You will need to verify actual static pressure 2 thirds downstream of the air handler with a Magnahelic gauge to confirm accuracy of your set point which controls inlet guide vanes or VFD. It is required to have a higher static than some have suggested so that when under a full load you will have an average of 1.5". Unless you want to stand around and regulate this control as needed...Let the equipment do the work. Lowering your static will do nothing whatsoever. As a matter of fact, the higher air static will identify problem areas such as dumping from a VAV box which has a bad motor or air valve. This can be checked by overriding control and closing or opening the air valve and checking air flow at the display.

Your balancing will be set up as two positions- Minimum airflow and maximum airflow. Minimum is based independently for cooling and more important for heating which will require airflow to meet its requirements. You will need to command the VAV's to self calibrate which is done in the set up. This is done by selecting calibration and choosing a Binary output for its operation. You will need to save it and wait a minute. Then choose its reference which is indicated by the three (...) for self calibration and a binary output as its reference.

In addition the calibration should be scheduled to perform by itself which is done through time of day scheduling just like you would start and stop times. This may need to be set up in CPL if it’s not already set up. This does not need to be performed every day but should be done once a week by itself.

It is not recommended to alter the set up for the VAV's other than set them up as their actual size. If you have a 12" round inlet it should be set up to it's corresponding CFM output which is around 2000 CFM. The air flow ring is designed to individually fit each different size box and accurately measure CFM.

I hope this helps.

___________________________________________
Trouble shooting is not part of the repair............understand the symptoms and you will find a solution.

Nice posts, alcomech. Plus, thanks for motivating me to get some printer ink! :grin2: :cheers:

dang! double posted!

Thanks Nuclrchiller I wrote that up for a guy about two months ago.