External control cont, Staging with primary/secondary mode, Staging with aquastat – WaterFurnace Envision Hydronic User Manual
Page 24: Nskw installation manual, Secondary unit
24
NSKW INSTALLATION MANUAL
Staging with Primary/Secondary Mode
Staging is only possible with dedicated heating or cooling
units. Reversible units cannot be staged. Staging can be
accomplished with primary/secondary modes or by using
an aquastat.
The first stage must be setup as a primary unit. All other
units must be setup as secondary units. The set point is
stored in the primary unit. Once the set point in the primary
unit has been satisfied, all units will immediately shutdown.
WARNING: Do not stage more than 6 units.
C
G
W1
L
X1
Y2
O
Y1
W2
S
X2
R
C
G
W1
L
X1
Y2
O
Y1
W2
S
X2
R
C
G
W1
L
X1
Y2
O
Y1
W2
S
X2
R
Primary Unit
(SL=0)
Secondary Unit
(SL=1)
First Stage Control Box
Second Stage Control Box
Third Stage Control Box
Secondary Unit
(SL=1)
Wiring for Primary/Secondary Unit Staging
First Stage
Second Stage
Third Stage
NOTES: X1 = Secondary output
Y1 = Compressor call
Staging with Aquastat
When staging units using an Aquastat, all units must be
setup as secondary units.
WARNING: Do not stage more than 6 units.
Secondary Unit
(SL=1)
Second Stage Control Box
First Stage Control Box
Secondary Unit
(SL=1)
C
G
W1
L
X1
Y2
O
Y1
W2
S
X2
R
C
G
W1
L
X1
Y2
O
Y1
W2
S
X2
R
Typical Aquastat
Wiring for Dedicated Heating or Cooling Units with
Aquastat
First Stage
Second Stage
NOTES: X1 = Secondary output
Y1 = Compressor call
R = 24 VAC
External Control cont.