York BP 090, BP120 installation manual Unitary, 5005, Norman, Products, York, Group, Drive, 73069

present, trace the wiring from Y1 “OUT” for incorrect wir- ing. If 24 volts is not present at the Y1 “OUT” terminal, the UCB must be replaced.

12.For units without economizers: If 24 volts is present at the Y1 “OUT” terminal, check for 24 volts at the Y1 “ECON” terminal. If 24 volts is not present, check for loose wiring from the Y1 “OUT” terminal to the Mate-N- Lock plug, the jumper in the Mate-N-Lock plug, and in the wiring from the Mate-N-Lock plug to the Y1 “ECON” terminal.

For units with economizers:If 24 volts is present at the Y1 “OUT” terminal, check for 24 volts at the Y1 “ECON” terminal. If 24 volts is not present, check for loose wiring from the Y1 “OUT” terminal to the Mate-N-Lock plug, a poor connection between the UCB and economizer Mate-N-Lock plugs, loose wiring from the Mate-N-Lock plug to the economizer, back to the Mate-N-Lock plug, and from the Mate-N-Lock plug to the Y1 “ECON” termi- nal. The economizer control may have faulted and is not returning the 24 volts to the Y1 “ECON” terminal even though the economizer is not providing free cooling. To

test the economizer control, disconnect the Mate-N- Locks and jumper between the WHITE and YELLOW wires of the UCB’s Mate-N-Lock plug.

13.The UCB can be programmed to lock out compressor operation during free cooling and in low ambient condi- tions. These options are not enabled by default. They can be checked by local distributors.

For units with factory installed economizers, the UCB is programmed to lock out compressor operation when the LAS set point is reached.

For units without factory installed or with field installed economizers, the UCB allows compressor operation all the time. This programming can be checked or changed by the local distributor.

14.If none of the above corrected the error, test the integrity of the UCB. Disconnect the C1 terminal wire and jumper it to the Y1 terminal. DO NOT jump the Y1 to C1 termi- nals. If the compressor engages, the UCB has faulted.

15.If none of the above correct the error, replace the UCB.

Subject to change without notice. Printed in U.S.A.	66307-YIM-B-0606
Copyright © 2006 by Unitary Products Group. All rights reserved.	Supersedes: 66307-YIM-A-0704/035-17277-004-A-0704

Unitary	5005	Norman
Products	York	OK
Group	Drive	73069