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Manual 2100-563C
Page 11 of 40
6. 2-Stage Compressor Units with Newer
ECONWMT Economizers (See Note A)
1
st
stage cooling set point is the setting (SP) input into
the controller. Factory default is 77F (25C). On a call
for cooling the blower of the
lead unit will come on
immediately (if not already on – See Blower
Operation), and the Stage 1 LED will blink for 10-
seconds before going solid, at which time the lead unit
Y1 cooling output turns on. If the outdoor temperature
and humidity conditions are below the set point of the
economizer control the lead unit economizer will
operate instead of the compressor. If outdoor conditions
are not acceptable for free cooling the compressor will
automatically operate on compressor Stage 1 partial
capacity instead of the economizer.
2
nd
cooling set point is 4F (default setting, user
selectable 2-6F) warmer than Stage 1. On a call for 2
nd
Stage cooling the blower of the lag unit is turned on (if
not already on – See Blower Operation), and the Stage 2
LED will blink for 10-seconds before going solid, at
which time the lag unit Y1 cooling output turns on. If
the outdoor temperature and humidity conditions are
below the set point of the economizer control the lag
unit economizer will operate instead of the compressor.
If outdoor conditions are not acceptable for free cooling
the compressor will automatically operate on
compressor Stage 1 partial capacity instead of the
economizer.
3
rd
cooling set point is 2F (default setting, user
selectable 2-3F) warmer than Stage 2. On a call for 3
rd
Stage cooling the lead unit economizer will continue to
operate as long as outdoor conditions are acceptable,
and the compressor will operate on compressor Stage 1
partial capacity. If outdoor conditions are not acceptable
for free cooling the lead unit compressor will
automatically be operating on compressor Stage 1
partial capacity and will go to Stage 2 full capacity
operation.
4
th
cooling set point is 2F (default setting, user
selectable 2-3F) warmer than Stage 3. On a call for 4
th
Stage cooling the lag unit economizer will continue to
operate as long as outdoor conditions are acceptable,
and the compressor will operate on compressor Stage 1
partial capacity. If outdoor conditions are not
acceptable for free cooling the lag unit compressor will
automatically be operating on compressor Stage 1
partial capacity and will go to Stage 2 full capacity
operation.
COOLING OPERATING SEQUENCES FOR
NON-ALTERNATING LEAD/LEAD/LAG/
LAG CONFIGURATION
Note: Heat pumps cannot be operated in Non-Alternating
Lead/Lead/Lag/Lag sequence. Selecting Heat Pump =
Yes will override a Non-Alternating selection and force
system to Alternating Lead/Lag/Lead/Lag sequence.
1. 2-Stage Compressor Units No Economizer
1
st
stage1
st
stage cooling set point is the setting (SP)
input into the controller. Factory default is 77F (25C).
On a call for cooling the blower of the lead unit will
come on immediately (if not already on – See Blower
Operation), and the Stage 1 LED will blink for 10-
seconds before going solid, at which time the lead unit
compressor will start in compressor Stage 1 partial
capacity operation.
2
nd
cooling set point is 4F (default setting, user
selectable 2-6F) warmer than Stage 1, at which time the
lead unit compressor will switch to compressor Stage 2
full capacity.
3
rd
cooling set point is 2F (default setting, user selectable
2-3F) warmer than Stage 2. On a call for 3
rd
Stage
cooling the blower of the lag unit will come on
immediately (if not already on – See Blower Operation),
and Stage 3 LED will blink for 10-seconds before going
solid, and then the lag unit compressor will start in
compressor Stage 1 partial capacity.
4
th
cooling set point is 2F (default setting, user selectable
2-3F) warmer than Stage 3. On a call for 4th Stage
cooling the Stage 4 LED comes on solid (no delay), and
the lag unit compressor will switch to compressor Stage
2 full capacity operation.
2. 1-Stage Compressor Units with Older EIFM
Economizers
1
st
stage cooling set point is the setting (SP) input into
the controller. Factory default is 77F (25C). On a call for
cooling the blower of the lead unit will come on
immediately (if not already on – See Blower Operation),
and the Stage 1 LED will blink for 10-seconds before
going solid, at which time the lead unit Y1 cooling
output turns on. If the outdoor temperature and humidity
conditions are below the set point of the economizer
control the lead unit economizer will operate instead of
the compressor. If outdoor conditions are not acceptable
for free cooling the compressor will automatically
operate instead of the economizer.
2
nd
cooling set point is 4F (default setting, user
selectable 2-6F) warmer than Stage 1. On a call for 2
nd
Stage cooling the lead unit Y2 cooling output turns on.
The lead unit economizer will close and the compressor
will operate. If the compressor is already running from
1
st
stage cooling call due to outdoor conditions being
outside of free cooling range no action occurs at 2
nd
stage set point.