15
®
Model MSX Make-Up Air
Installation of Building Pressure
Control (optional)
1. Mount Pressure Tap
Using the factory provided bracket, mount the
pressure tap to the
outside of the unit.
Choose a location
out of the prevailing
winds and away from
supply or exhaust
fans to assure
accurate readings.
2. Run Pressure Tap Lines
Run a pressure tap line from the pressure tap on the
outside of the unit to the low pressure tap on the back
of the photohelic gauge. Run a second pressure tap
line from the high pressure tap on the back of the
photohelic gauge to the space. Fifty feet of tubing is
supplied with the unit.
3. Set the Building Pressure
The pressure gauge is used to set the desired building
pressure. The pressure is set by adjusting the knobs
for the upper and lower pressure limits. Typical
settings are 0.0 inch wc for the lower and 0.10 inch wc
for the upper pressure setting.
Connections for Photohelic Gauge
Factory
Wiring
High Pressure
Tap
to Space
Low Pressure
Tap
to Outside
Typical Photohelic Gauge Settings
Pressure Setting Knobs
Pressure Setting
Needles
Pressure Indicating
Needle
