[A And Iv/Pr (H8)] - Daikin Microtech III Operation And Maintenance Manual

■ Remote shutdown
• A simple grounded signal puts the unit into the
shutdown mode. Remote shutdown is provided
so that when properly connected to a water
loop controller or remote switch, the emergency
shutdown input can be used to shut down the
water source heat pump. Compressor and fan
operations are suspended, and an a unique two
external LED status is generated.
Remote shutdown process operation:
When the E terminal is grounded, the MicroTech III unit
controller enters remote shutdown mode. Remote shutdown
is provided so that when properly connected to a building
automation system, remote switch, etc., the E terminal can
be used to shut down the water source heat pump.
Figure 7: Terminal "E" - grounded for remote shutdown
When in remote shutdown (E terminal grounded),
thermostat and control inputs have no affect upon unit
operation. No faults or modes have higher priority than
remote shutdown.
MicroTech III LED Status – Remote Shutdown
Yellow
Off
Remote shutdown and brownout condition have the
same level of priority. See Table 10 on page 19.
When the unit is in remote shutdown mode, the following
occurs:
1 . Both compressors and electric heat are de-energized.
2 . The fan de-energizes (if enabled).
3 . Fault terminal (A) will remain de-energizes because
emergency shutdown is a "mode". A to C will be
used to indicate normal operation.
When the E terminal is no longer grounded the unit will
automatically return to normal operation.
Note: The remote shutdown input (E) will suspend unit
operation. Disconnect power when servicing the
unit/controller.
OM 1239
Green Red
Flash Off
M
■ Invalid jumper configuration
• The invalid configuration alarm is generated and
locks out control when; the hardware jumpers
are set to an invalid model type setting; or if an
incompatible I/O expansion board software input/
output type identification number is detected
and the I/O expansion board is required by the
baseboard jumper JP8.

[A and IV/PR (H8)]

The control outputs are Alarm Fault (A) and Isolation
Valve / Pump Request [IV/PR (H8)]. The operation of the
control outputs during occupied mode is as follows:
■ The thermostat alarm output: Will be energized when
there are fault conditions presently active. Without any fault
conditions active, the alarm output shall be de-energized.
■ Isolation valve / pump request [IV/PR (H8)]: is
selectable to be energized when the compressor
is off (normally closed), or when the compressor is
on (normally open), by moving the wire lead to the
appropriate terminal.
Figure 8: H8 terminals on MicroTech III board
■ Reversing valves 1 & 2: 24V signals that are
energized upon a call for heat mode on each circuit
■ Compressor relay: Line or low voltage output used
to control both compressors. (On/Off)
Fan operation
The G terminal controls continuous fan operation. The
fan runs continuously when the G terminal is energized.
When the G terminal is de-energized, the fan cycles with
the compressors.
16
t III u C
ICro eCh nIt ontroller
www.DaikinApplied.com