Replacing A Microtech Iii Circuit Board; Initial Power-Up; Pre Start Check List - Daikin MicroTech III Operation & Maintenance Manual

CAUTION
The MicroTech III circuit board incorporates static sensitive
devices. A static charge from touching the device can damage
the electronic components. To help prevent damage during
service, use static discharge wrist straps.Static discharge wrist
straps are grounded to the heat pump chassis through a 1 Mohm
resistor.
Replacing A MicroTech III
Circuit Board:
1. Connect wrist strap to unit.
2. Remove faulty board and place on static protected
surface.
3. Remove replacement board from static protected bag.
Do not touch circuit board; hold by edges.
4. Holding board in grounded hand, install board in unit.
5. Insert faulty board in empty static bag for return.
Table 2: Configuration Jumper Settings
Baseboard Description
Normal / Test Mode
Fan Operation
Loop Fluid
Alarm "A" Terminal Output Polarity
Room Sensor Setpoint
Potentiometer Range
Thermostat / Room Sensor
Not Used
Not Used
WARNING
Proper antifreeze/water solution is required to minimize the
potential of fluid freeze-up. Jumper JP3 is factory set for water
freeze protection with the jumper open. Operation with anti-
freeze protection requires JP3 to be field configured for the
jumper closed. If unit is employing a fresh water system (no
anti-freeze protection), it is extremely important that JP3 jumper
setting remains in the open position (factory default setting) in
order to shut down the unit at the appropriate water temperature
to protect your heat pump from freezing. Failure to do so can
result in unit damage and fluid leaks."
OM 931-6 • MicroTech III Unit Controller for WSHP
Jumper(s) Jumper Setting
Open
JP1
Shorted
Open
JP2
Shorted
Open
JP3
(see warning)
Shorted
Open
JP4
Shorted
Open
JP5
Shorted
Open
JP6
Shorted
JP7 Open
JP8 Open
M

Initial Power-Up

Pre start check list:

A random start delay time between 300 and 360 seconds
is generated at power up.
Figure 2: Location of Configuration Jumpers on the Base
Board Controller
Normal Operation
Service / Test Mode
Continuous Fan Operation (On), when not operating in the unccupied mode.
Cycling Fan Operation (Auto)
Water Loop Fluid (water freeze protection - factory default setting)
Glycol Loop Fluid (Systems with anti-freeze protection)
Fault de-energizes alarm output to 0VAC.
Fault energizes alarm output to 24VAC.
Short Range: -3 to +3 ºF (-1.67 to +1.67 ºC)
Long Range: 55 to 95 ºF (12.78 to 35 ºC)
Thermostat Control
Room Sensor Control
6
t III u C
ICro eCh nIt ontroller
Function
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