External control cont, Staging with primary/secondary mode, Staging with aquastat – WaterFurnace Envision Hydronic User Manual

Page 24: Nskw installation manual, Secondary unit

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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.

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