Service manual

A DJM3.2 MANUAL
= 10ºC scale as the temperature readout. This scale is fairly accurate from 15 to 25ºC. As
temperatures approach 45ºC, the scale reads 2 to 4ºC below actual.
NOTE: There are different calibration procedures for Johnson TE 6100 and the DJM3.2
face mounted set-point.
Johnson Set Point While Set at 21°C
1. Measure the DJM3 set-point across Resistor R124 and adjust Pot Dis SP Cal (located next to
terminal U) until the voltage reading is 2.1 volts.
Built In Set-Point
2. While set at 21ºC, measure the DJM3.2 set-point across Resistor R124. Loosen the set-screw on
the set-point knob and move the knob to the setting that agrees with the measured value. Tighten
the set-screw and return the dipswitches to their normal position.
For either of the above:
3. Return the dipswitches to their normal position.
Room Sensor Calibration
1. Measure the room or return air temperature and set the room set-point dial to the measured value.
(Some units have room mounted sensor/set-point dials, some have separate room set-point dial with sensor
on return air.)
2. Record the settings of dipswitches 1, 2, and 3. Turn off dipswitches 1, 2, and 3.
3. Measure the DJM3.2 calculated set-point. (See Section XVIII.)
4. Turn dipswitch 3 on.
5. Measure the DJM3.2 calculated set-point DC voltage again. Adjust Pot Room Cal (located next to
terminal OR) until the voltage is the same as was measured in step C. If the room is satisfied, there
is no reset.
6. Return the dipswitches to their normal position.
BMS Calibration and Set Up
Refer to notes for BMS on Page 14.
Page 26 Revised: 3/11/99