surface and mark locations for holes to be drilled.
Remove the panel and drill 2 holes (hole size to match
field supplied lag bolts and anchors). Place panel over
the holes and secure it using bolts.
ELECTRICAL WIRING
Electrical connections of the control panel use 18
ga wire for all external wiring. The control panel
requires 24 Vac which is provided by the NORTEC
supplied step down transformer (120 Vac to 24 Vac).
The transformer plugs into any standard 120 Vac
outlet that must be located within 6’ (six feet) of the
control panel. Power is connected to the low voltage
terminal trip located inside the panel as illustrated in
Figure #16 (“Control Panel Terminal Strip Interfaces”).
Control panels are supplied by NORTEC in two
configurations. The first is for use with systems that
are designed to operate with only an On/Off humidistat
and the second is designed to operate with a
modulation controller. Within the control panel there is
a 7 point terminal block, terminals 6 & 7 are for power
voltage 24 Vac. A wiring diagram is provided with
each control panel. Both control panels reserve
terminals 1 & 2 are for on/ off control wiring which may
be a simple humidistat, a relay for remote operation or
other interlock devices (dry make break contacts).
Modulation controlled systems use terminal 3, 4 &
5 on the 7 terminal block strip as follows: terminal 3 is
to be connected to the “+” terminal on the controller,
terminal 4 is to be connected to the “-“ terminal on the
controller and terminal 5 is for 24 Vac supply to the
controller. This is illustrated in Figure #15 (“Control
Panel Terminal Strip Interfaces”).
PILOT LINES
All air pressure lines connecting to the control
panel must be 1/4” O.D. plastic tubing suitable for 150
psig. Figure #16 (“Schematic Plumbing Layout”)
illustrates the proper connections of the air supply to
the Control Panel and from the control panel to the
vacuum valve and the pilot air regulator. The control
panel requires an input pneumatic (air) control supply
which is usually tapped off the main air supply line
upstream of the pilot air regulator. The control panel
has two pneumatic fittings located on its top plate; one
marked “pilot in” and the other marked “pilot out”. The
“pilot in” gets connected to the control supply with the
1/4” plastic tubing. A second 1/4” line connects the
“pilot out” to both the pilot air regulator and the vacuum
valve using a “T” connector.
- 10 -
PRV
-P
ILOT
PRV
PRV
Primary Water Pressure Control
Primary Air Pressure Control
Ball Valve
Ball Valve Water Side
Vacuum Valve
Pilot Air Regulator
Nozzle
Pilot Line
Control
Panel
Single Zone Configuration
Figure #16
Schematic Plumbing Layout
1
2
3
4
5
7
6
24 Vac
On/Off
Controls
Modulation
Input
Optional
24 Vac
- +
Figure #15Control Panel Terminal Strip Interfaces
