McQuay WSC Operating Manual page 35

MODES Setpoints
Figure 20, MODES Setpoint Screen
Table 18, MODE Setpoint Settings
Description No.
Comp # 2 Stage
14
Sequence
Comp # 2 Mode 13
Comp #1 Stage
12
Sequence
Comp #1 Mode 11
Max. Comp. ON 10
BAS Protocol 9
Hot Gas Control
8
Point
Hot Gas Bypass
7
Mode
Cond Pump 6
Evap Pump 5
Available Modes 4
Control Source 3
Unit Mode 2
Unit Enable 1
OM Centrif Micro ΙΙ-5
Default Range
1 1,2, ... (# of Compressors)
Normal, Efficiency, Pump,
Normal
Standby
1 1,2, ... (# of Compressors)
Normal, Efficiency, Pump,
Normal
Standby
1 1-16
None, Local, Remote,
Modbus BACnet, LonWorks,
MODBUS,
30% 20 to 70%
Normal Off, Water LWT, %RLA
Pump #1 Only, Pump #2
Pump
Only, Auto Lead, #1 Primary,
#1 Only
#2 Primary
Pump #1 Only, Pump #2
Pump
Only, Auto Lead, #1 Primary,
#1 Only
#2 Primary
COOL, COOL/ICE, ICE,
COOL
COOL/HEAT, HEAT
LOCAL LOCAL, BAS, SWITCH
COOL COOL, ICE, HEAT, TEST
OFF OFF, ON
Pass-
Comments
word
Sets sequence number for # 2 compressor, if 1 it is
M
always first to start, if 2 is always second (Note 1)
Normal uses standard sequencing
Efficiency starts one compressor on each dual unit
M
Pump starts all compressors on one chiller first
Standby uses this compressor only if another fails.
Sets sequence number for # 1 compressor, if 1 it is
M
always first to start, if 2 is always second (Note 1)
M Ditto No. 12.
M Total number of compressors minus standby
Sets BAS Standard Protocol to be used or LOCAL
M
if none.
T LWT or % RLA below which HGBP solenoid is on
T Sets mode for hot gas operaton
Pump #1 Only, Pump #2 Only, use only these
pumps
M
AUTO, balance hours between #1 and #2
#1 Primary, #2 Primary, if primary fails, use other
Pump #1 Only, Pump #2 Only, use only these
pumps
M
AUTO, balance hours between #1 and #2
#1 Primary, #2 Primary, if primary fails, use other
T Sets modes that can be selected in SP 2
O Sets control source
Selects from MODES in SP4
OFF, everything is off. ON, Evap pump on, comp,
O
cond pump and tower on as required to meet LWT
35