View Full Version : rooftop economizer problem
01-23-2006, 09:03 PM
Honeywell solid state economizer logic module led lighted all the time, even if there is no power to Y1 . it is one stage rooftop. when I jumped Y1 and R, compressor run at once and led lighted. when I take the led form the oa senser, led is off, but the compressor keep on runing. the ambient temperature is about 32f. I am not sure the oa sensor has problem or the logic module. is there anyway to pin it down
when the led is on, it is indicating that your outdoor air is below the enthalpy set point. jumping R to Y1 should drive the damper open. Remember that the economizer module is powered in parralel to the indoor blower and only provides switching for the power to the compressor contactors.
The problem that you're detailing here may be either the outdoor sensor, the module or both. Economizers are not difficult, but there is not enough room here to go into details and all the possibilities.
Spring will be here soon and supply houses will have economizer classes coming up. I highly recommend the course put out by your local York dealer. If you're in the Chicago area, get to Mike Bishop's class. He's a great instructor.
01-23-2006, 10:42 PM
Two things you should always carry. A Temp/resistance chart for checking sensors and a spare logic module.
Start here and enter economizer in the product search http://customer.honeywell.com
[Edited by incontrol on 01-23-2006 at 10:48 PM]
01-23-2006, 10:55 PM
thank you. I have the menu.I usually can not tell which compont is defective, oa sensor or logic module. the led should be off when the Y1 has no power, no matter what the outdoor temperature. here it is keep on lighting. I am thinking whether I can just change one parts instead both.
01-23-2006, 11:30 PM
I made a rig with a 1.2k ohm resistor, wire and a few terminals.
Basically you trick out the logic mod to think it's 55deg. You can troubleshoot the whole economiser system in 5 min. by switching the enthalpy control points. (A,B,C,D)
02-12-2006, 02:55 AM
The led will be on when the indoor fan is running AND the our door air is cold enough to give cooling below the abcd enthalpy setting
It has nothing to do with power to y1 y1 power goes to the relay terminals on the entlalpy module
the red light will be on regardless of a call for cooling if the temp is below the outdoor sensor enthalpy setting.
you are correct in thinking its either the sensor or the enthalpy control, also consider wiring and connections too if you have a bad connection you may also see this problem
02-14-2006, 12:54 AM
Just out of curiosity, is this a york rooftop package unit?
02-14-2006, 10:14 AM
I will make a very informed bet that it's the enthalpy sensor if it's more than 2 years old.
02-14-2006, 04:24 PM
yes, it is york. after I changed the new logic control board and oa sensor, the rooftop still run directly compresor. checked the diagram throunghly, found a jump between Y1 and Y2 in the control board. the unit has been on the roof more than 10 years. I think it is never run free cooling since it is installed.
Powered by vBulletin® Version 4.2.0 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.