York YCAS0098EB, Installation Operation & Maintenance, Page: 170 / 184

170
JOHNSON CONTROLS
Turn on a Fan Stage
Every 5 sec
285 PSIG
Turn on a Fan Stage
every 15 min
250 PSIG
Discharge Pressure 150 – 250 PSIG
150 PSIG
Turn off Fan Stage
every 15 min.
120 PSIG
Turn off a Fan Stage
every 5 sec.
0 PSIG
Note: A low Oil - Suction differential Pressure less than 75 PSID
will cause the micro to turn a fan stage Off every 5 sec. This
will override pressure control of the fans.
EPROM Version C.A14.09.03 (A85F),
other .03 versions and higher
Fan operation is outlined in Table 6. Condenser fan ON
conditions are governed solely by the Discharge Pressure
(DP). When the DP rises above 205 PSIG, fan stage 1 is
activated. From there, subsequent fan stages are activated
as the discharge pressure rises. The system will remain at
the highest fan stage reached unless the OFF conditions
outlined in the next paragraph are satisfied.
Condenser fan OFF conditions are governed by both the DP
and OAT. Fan staging will be decreased from the highest
fan stage reached if both the DP and OAT requirements
are met. For example, if a system is at fan stage 3, and the
DP falls below 195 PSIG and the OAT drops below 75°
F, the fan stage will be reduced to stage 3.
TABLE 5 – CONDENSER FAN CONTROL
(EPROM VERSIONS C.A32.09.02 (0483),
C.ACS.09.02 (D87E), AND C.A06.09.03
(EIOC)
Fan ON * OFF * Fan Wire Relay
Stage Fans Conditions Conditions Contactor Number Board
DP DP & OAT
Output*
1 1 >205 PSIG <135 PSIG & <60°F 9M 130 15
SYS1 2 3 >265 PSIG <160 PSIG & <65°F 10M 131 14
3 5 >285 PSIG <180 PSIG & <70°F 11M 132 10
4 1, 5 >205 PSIG <135 PSIG & <75°F 9M, 11M 130, 132 10,15
SYS2 5 3, 5 >265 PSIG <160 PSIG & <80°F 10M, 11M 131, 132 10, 14
6 1, 3, 5 >285 PSIG <180 PSIG & <85°F 9M, 10M, 11M 130, 131, 132 10, 14, 15
TABLE 6 – CONDENSER FAN CONTROL AND FAN CONTACTOR DATA FOR DXST UNITS
WITH 3 FANS/SYSTEM (EPROM VERSIONS C.A14.09.03 (A85F), OTHER .03 VERSIONS, AND
HIGHER
* Sys 1 Outputs are on Relay Board #1
Sys 2 Outputs are on Relay Output Board #2
Micro Panel Contents