Bard MC500 Series User Manual

FIGURE 12
Alternating Sequence Cooling
Alternating the staging will always bring on ALL
economizers (when used and conditions allow) before
any compressors are started. If no economizers are
installed on single stage units, the mechanical cooling
will start in sequence.
NOTE: When an economizer is used with two stage
units, there is one more stage per unit (when
available). In this example, there are nine total
stages. The last three stages are activated by
the JADE control.
Manual 2100-746D
Page 29 of 59
FIGURE 13
Non-Alternating Sequence Cooling
Stage Unit 1 Unit 2 Unit 3
1 Y1 OFF OFF
2 Y1 Y1 OFF
3 Y1 Y1 Y1
4 Y1, Y2* Y1 Y1
5 Y1, Y2* Y1
6 Y1, Y2*
G
G
G
* For two stage units with economizers in alternating sequence,
2
nd
stage mechanical cooling will be activated by the JADE
TM
control base on time (default TD 15 minutes). In this
example, full load mechanical will start 15 minutes after Y2
is energized (delay time is adjustable in JADE setup).
Non-alternating setup will always bring on ALL stages
of the lead unit before calling on unit 2 and so on.
Y1 would be economizer (if available); Y2 would be
mechanical cooling.
NOTE: When an economizer is used with two stage
units, there is one more stage per unit (when
available). In this example, there are nine total
stages. The last three stages are activated by
the JADE control.
Stage Unit 1 Unit 2 Unit 3
1 Y1 OFF OFF
2 Y1, Y2* OFF OFF
3 Y1, Y2* Y1 OFF
4 Y1, Y2* Y1, Y2* OFF
5 Y1, Y2* Y1, Y2* Y1
6 Y1, Y2* Y1, Y2* Y1, Y2*
G
G
G
* For two stage units with economizers in non-alternating
sequence, 2
nd
stage mechanical cooling will be activated by
the JADE
TM
control base on time (default TD 15 minutes). In
this example, full load mechanical will start 15 minutes after
Y2 is energized (delay time is adjustable in JADE setup).

Bard MC500 Series Specifications

General

Brand	Bard
Model	MC500 Series
Category	Controller
Language	English