York PREDATOR 120 Installation Manual page 44

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"
terminal. 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.
Subject to change without notice. Printed in U.S.A.
Copyright © by Unitary Products Group 2003. All rights reserved.
Unitary
Products
Group
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 York distributors.
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.
5005
York
Drive
035-17311-002-A-0803
Supersedes: 035-17311-001-A-1202
Norman
OK
73069