External control – WaterFurnace Envision Hydronic (NSW) User Manual

Page 24

NSW INSTALLATION MANUAL

Y1 = Compressor call

R = 24VAC

Control Box

Typical Aquastat

Secondary Unit

(SL=1)

Aquastat Wiring for Dedicated Heating or Cooling Unit

Y1 = Compressor call
O = Reversing valve call
R = 24VAC

Note: Jumper wire must be
moved to terminals 5 & 6.

Secondary Unit

(SL=1)

Typical Aquastat

Jumper

Wire

Control Box

Aquastat Wiring for Reversible Unit

External Control

Primary Mode

In dedicated heating or cooling units, the unit is controlled

by the internal controller. Compressor output is determined

by the entering load-side water temperature.

The secondary output will be energized if two

conditions occur:

1. The initial temperature is greater than IC away from the

set point.

2. The change in temperature in a given period of time P is

less than d.

In a reversible unit, the unit is controlled by the internal

controller. Compressor output is determined by the

entering load-side water temperature. For reversible units,

the jumper wire must be positioned across terminals 6 and

7, (factory default set to this position). Reversible units do

not have a secondary output.

NOTES: SL in the configuration menu must be set to 0,

(factory default). All parameters should be checked for each

application on primary unit, (refer to the parameter table).

Secondary Mode

In dedicated heating or cooling units, secondary mode

allows the unit to be controlled by an external source.

Compressor output is determined by the Y1 input only.

The secondary output will be energized after the following

condition occurs:

1. The change in temperature in a given period of time P is

less than d.

In reversible units, secondary mode allows the unit to

be controlled by an external source. Compressor output

is determined by the Y1 input and the reversing valve

is determined by the O input. In reversible units, the

jumper wire must be positioned across terminals 5 and 6.

Reversible units do not have a secondary input.

NOTES: SL in the configuration menu must be set to 1. P

and d must be setup for each secondary unit.

Wiring an Aquastat - Reversible Unit

• To create a secondary unit, set SL to 1 in the

configuration menu.

• Position the jumper wire in the control box across

terminals 5 and 6.

WARNING: Reversible units cannot be

staged.