York Millennium YCAS 316, Installation Operation & Maintenance, Page: 103 / 144

FORM 201.10-NM1
103
YORK INTERNATIONAL
NOTE: It will be required to program a value for each
system.
The allowable range of DESIGN COND TEMP. is 100 -
140°F (37.7-60°C) with the default set for 125°F (51.7°C).
The DESIGN SYSTEM COND TEMP. is password pro-
tected under the PROGRAM key. The displays will ap-
pear as follows:
Program the design temperature for the respective sys-
tem and press ENTER. Repeat for the other system. This
value is not password protected and can be programmed
anytime the PROGRAM key is pressed.
The LAG COMPRESSOR START POINT % is program-
mable in the Program mode. By selecting a LAG COM-
PRESSOR START %, the user is actually selecting the
% slide valve at which the lead compressor is allowed to
load, before the lag compressor is brought on. This % is
programmable from 40 - 99%.
NOTE: This is in contrast to Scheme 1 where LAG
COMPRESSOR START % relates to % FLA.
The micro will start the lead compressor whenever the
chilled liquid temperature is above the High Limit of the
Control Range (CR) and the 3 minute “Start Timer” has
timed out. The 3 minute “Start Timer” is the minimum
amount of time that the compressor must remain off af-
ter a cycling shutdown (Anti-Recycle Timer Timed Out)
or after power is first applied. Once started, the micro
will pulse the slide valve to load the lead compressor to
bring the chilled liquid temperature within the NEUTRAL
ZONE.
If temperature is not brought down to within the “Neutral
Zone”, the lag compressor will be brought on by the mi-
cro after the lead compressor loads up to the programmed
LAG COMPRESSOR START POINT % as determined
and programmed by the user.
If due to system conditions, the lead compressor does
not reach the programmed %, even though the lead com-
pressor may be fully loaded, the lag compressor will start
regardless of the programmed Start % after 5 minutes of
operation. This will occur whenever the lead compressor
cannot bring the LWT to within 2.0°F of the high end of
the CONTROL RANGE (CR). Once the lag compressor
is started, equalized loading and unloading of the two
compressors will occur based on slide valve %.
The 5 minute default for lag compressor start assures
that the lag compressor will start and load in situations
where error is introduced into the micro calculation for
computing slide valve %. These situations may occur
due to tolerances in discharge pressure transducers,
ambients, dirt on coils, subcooling, superheat, etc.
As mentioned above, after the lead compressor starts
and loads up to the programmed 40 - 99%, if tempera-
ture is still above the CONTROL RANGE (CR), the lag
compressor will come on. It will then be brought up to a
TABLE 5 – CHILLER SYS 1 AND SYS 2 MOTOR CURRENT = 100% FLA
MODEL 200 VOLTS (-17) 230 VOLTS (-28) 460 VOLTS (-46) 575 VOLTS (-58)
YCAS ENGR. DATA SYS 1 FLA SYS 2 FLA SYS 1 FLA SYS 2 FLA SYS 1 FLA SYS 2 FLA SYS 1 FLA SYS 2 FLA
140 6A2A2KN6A 338 338 294 294 147 147 118 118
160 6M4M4KN6A 406 406 354 354 176 176 141 141
170 6F5M5NN6A 484 484 421 421 210 210 169 169
180 6F5F5NN6A 484 484 421 421 210 210 169 169
190 6H6F5NN6A 598 484 522 421 259 210 207 169
216 6P7H6NN6A — — — — 320 259 254 207
236 6P7P7NN6A — — — — 320 320 254 254
246 6S7S7NN6A — — — — 320 320 254 254
216x 10H5H5NN6A — — — — 210 210 169 169
236x 10P6H6NN6A — — — — 259 259 207 207
266x 10S7S7NN6A — — — — 320 320 254 254
S Y S T E M 1 C O N D T E M P
1 1 8 . 0 ° F = 1 0 0 % L O A D
TABLE 6 – CHILLER SYS 1 AND SYS 2 DESIGN
CONDENSING TEMP (CTP)
MODEL FOR ALL VOLTAGES
YCAS ENGR. DATA SYS 1 CTP SYS 2 CTP
140 6A2A2KN6A 116.1°F 116.1°F
160 6M4M4KN6A 118.3°F 118.3°F
170 6F5M5NN6A 121.3°F 118.5°F
180 6F5F5NN6A 121.4°F 121.4°F
190 6H6F5NN6A 124.3°F 121.4°F
216 6P6H5NN6A 128.8°F 124.4°F
236 6P7H6NN6A 128.8°F 128.8°F
246 6P7P7NN6A 130.1°F 130.1°F
216x 10H5H5NN6A 115.4°F 115.4°F
236x 10P6H6NN6A 118.6°F 115.3°F
266x 10S7S7NN6A 119.6°F 119.6°F