Dexon Canada Air Systems Inc
OWMDH Series Use Manual
Version 07.2019
Page
15
DEXON 95DH MAIN CONTROLLER TEST PINS DESCRIPTION
NOTE:
We recommend using “Minigrabber” type test leads that clip/hook on to the test pin holes for
measurements on the main controller to prevent accidentally shorting out test pins to components in
close proximity. IMPORTANT: When taking measurements the voltage does not equate exactly to
temperature, there is a 0.1VDC offset; for example (0.7VDC = 6
°
C), (1.1VDC = 10
°
C), (0.9VDC = 8
°
C).
TEST PIN
DESCRIPTION
COM
- Is the common pin for all 95DH Main Controller and Airflow Circuit Board voltage
tests (0-24VDC Range). The negative from a DC Volt Meter goes here for each
sampling.
DP
- Is the Discharge actual temperature as per the temperature sensor located near
the bottom of the blower heater in a small aluminum tube (See Dexon 95DH Main
Controller for Temperature Sensor Jack).
SP1
- Is the set point temperature that will be maintained at the blower heater
discharge at the bottom of the blower heater. The desired temperature may be
adjusted by turning “SP” (Set Point discharge temperature adjustment
potentiometer) clockwise to increase or counter clockwise to decrease. Typical
range is +5°C to +10°C (0.6VDC to 1.1VDC). IMPORTANT: Please contact Dexon
Canada Air Systems Inc. (403-272-0562) before making any adjustments to any
potentiometers. Note: the airflow in
“Auto” mode is preset by Dexon based on
airflow requirements and heating capacity. Increasing the airflow should only be
done if airflow is inadequate due to unforeseen on-site piping/ducting friction.
Adjustments should only be made when absolutely necessary and by qualified
personnel.
SP2
- Is the set point at which the stage 2 element will engage in order to maintain SP1
set point. As the outdoor temperature drops the stage 2 elements are called upon
to provide heat when the DP (down pipe) temperature sensor drops to where the
SP2 set point is set. Typically 0.5VDC = +4°C.
SP3
- Is the set point at which the stage 3 element will engage in order to maintain SP1
set point. As the outdoor temperature drops the stage 3 elements are called upon
to provide heat when the DP (down pipe) temperature sensor drops to where the
SP3 set point is set. Typically 0.35VDC = +4.5°C.
SP4
- Is the low temperature automatic restart set point. This is the temperature at
which the blower heater will automatically restart after a
“Low Temp.” shut down
has occurred.
A “Low Temp.” shut down occurs when the discharge temperature drops below
0°C and the fan shuts down to prevent freezing of the space. As the outdoor
temperature warms up the fan will automatically reset and start up based on the
SP4 temperature set point. Typically 0.2VDC = +1°C.
, Website:
Tech Support Phone: 403-930-1284, Admin Phone: 403-272-0562
