Krueger | 1401 N Plano Rd | Richardson, TX 75081 | 972.680.9136 | [email protected] | www.krueger-hvac.com
Installation, Operation, & Maintenance for CRFF-E Series
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ON/OFF Switch - Speed/Airflow Ad
j
ustment
All CRFF-E series units are equipped with a two-position rocker switch (ON/OFF), which is located on the side of the
electrical box, on top of the unit. Unless otherwise specified, units are furnished with a Universal Control Card to
enable adjustment of airflow or set to preferred communication mode.
Note: The CAT5e/RJ45 network ports are non-directional (in or out). Be sure to examine your cabling to insure that
there is no cross-over wired cables.
CAT 5e
Network Cable Connection
(RJ45 Connector)
ON/OFF Switch
RPM Test Probe Jack Comm.
Filter Indicator Light
Pressure Switch Adjuster
Manual Speed Potentiometer
Filter Indicator Light Option
The pressure switch for the filter indicator light option is set at 0.60 in wc from the factory. The set point for the
pressure switch can be adjusted between 0.50 in wc and 3.00 in wc by turning the set screw, accessible for the front of
the control enclosure. Counterclockwise rotation will increase the set point differential for switching; clockwise rotation
will reduce the set point.
The process to adjust this for a specific application is detailed below:
1. Adjust fan to highest setting
2. Measure and note initial pressure differential between ceiling plenum and unit plenum (downstream of the fan
and upstream of the filter)
3. Restrict discharge airflow incrementally to increase differential pressure until measured value matches filter
loading requirements for the project
a. If no specific filter loading requirements are specified a general recommendation is to use twice the
pressure differential measured in step 2
4. With the unit discharge blocked, adjust the set point of the pressure switch
a. If the indicator light is illuminated, increase the set point of the pressure switch (CCW rotation) until the
light dims
b. If the indicator light is still dim, slowly decrease the set point of the pressure switch (CW rotation) until the
light illuminates
5. Remove obstruction(s) from the unit discharge
6. Adjust fan speed to operational set point
Summary of Contents for CRFF-E
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