Hit the test pins. First jump is blower, second jump is economizer wide open.

Set the enthalpy control to "d" which will be a more aggresive economize.

Jump out y1 and econmize should energize if conditions are right.

Check under the economizer screens, the oat sensor is there, if they are older machines, most sensors will be corroded on the contacts and not work.

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If they are Ipak (IntelliPak) units your in a whole new world of controls.

Exhaust fans on any of these? That is something to consider.

In essence economization really is not that hard, but apparently scares the living tarnation out of a lot of guys. If your dealing with Honeywell economization modules, be prepared to upgrade to the JADE platform since Honeywell has discontinued all the W7*** series modules and combined them all into the JADE. Will need new sensors, too.

At a minimum you will have the economization module, a temperature or enthalpy sensor taking in the outdoor information, a mixed air sensor in the blower compartment, and an actuator that is driving the dampers open and close.

A big thing many are confused about on Honeywell modules is the "N" terminal. This is usually tied directly back to the thermostat terminal board. It must have 24v to it for the economizer module to operate. Seen too many times an economizer is condemned since the tech did not realize that someone had either removed a jumper at the thermostat board or simply N was disengaged for some reason. The whole purpose for N is to be utilized with commercial thermostats wit the A or OCC terminals. Whn the building is in occupied mode at the thermostat the economizer will turn on and go to the minimum position setting for the dampers and wait for a call for cooling. In unoccupied mode the N terminal is de-energized and the dampers close 100% and economizer is in stand-by mode....just a word of wisdom.

If the module has Exhaust output, this is based on two things, the damper open percentage or IAQ needs. The exhaust fan(s) can be energized when the dampers open a certain amount. Or there may be CO or other air quality sensors, pressure transducers, etc that can be set to initiate the exhaust fan(s) when they reach a predetermined setting.

Half the time I find the economizer and exhaust fans were factory or field installed, but never commissioned. Just setting there virgin since day of install.......more common than you would think.

Push to get your PRO status, there is a lot of economizer info, literature, and troubleshooting guides in those forums. There use to be a very good YouTube vid on troubleshooting economization. It was being performed on a Carrier unit, but I believe it has been removed, searched for it a few weeks back and could not find it. Should have saved it.

 

Good info

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Wow this could save my life. Thanks for the great info.

 

trane ecoomizers



hello, I am sure you know there are many steps in the setup process. first if there is an automation system controlling the rtu's you will need to check to see if there is any control from the bas. I would suggest isolating the bas from the rtu's. in stand alone mode you should be able to setup units. try to step up each unit the same....then you should be able to monitor and isolate the problem units. here is where the bas can help. some trend data will be your eyes and ears. this said if you problem you having is something this "unit will not economizer and seems to lock out on low ambient" my suggestion is to check the multi compressor module (mcm). you will need to remove one or two other boards that stack on top of it....the look at the chip on this board. it is a 32 pin removable. but do not remove....if the label is version 0113-26.19....you have a defective chip and will need to be replaced with version 26-20...the factory may / will be slow in replacing this chip.......but i think this is you fix....good luck with local trane service....

 

Just a note to you guys on economizer enthalpy settings.

When you have A, B, C, and D choices for enthalpy, setting it to D will mean you're bringing on mechanical cooling sooner. Setting it to one of the previous letters allows increasingly warmer air to be used for cooling.

For example, I was on a roof yesterday, and another customer's unit came on in cooling. It was 47 degrees out. I opened the unit and found the enthalpy set to D. I moved it to just before C, got a green free cooling light, and the compressor shut down while the dampers started to open. The potentiometers on these controls go off scale very easily, so now is the time to set them to work properly.