Microtech 2300 - Unit Status; Remote Shutdown

SEqUENCE OF OPERATION
MICROTECH 2300 UNIT CONTROLLERDAIKIN APPLIED
12
operate at the full load cooling CFM).
If at any time the EWT rises above the entering water
temperature setpoint plus 5°F (while operating) or below 45°F,
the 3-way valve will de-energize, disabling WSE operation.
If WSE is not available due to entering water temperatures out of
range, the sequence becomes:
• On a call from Y1 or cooling stage 1 setpoint, the unit
operates at part load mechanical cooling. (The fan will
operate at the part load cooling CFM).
• On a call from Y2 or cooling stage 2 setpoint, status the
same as above
• On a call from Y3 or cooling stage 3 setpoint, the unit goes
to full load mechanical cooling. (The fan will operate at the
full load cooling CFM).
The minimum o󰀨 timer of 360 seconds starts. If the loop
temperature increases above the changeover temperature,
waterside economizer mode will be suspended and the unit will
resume normal mechanical cooling mode with stage 1 of the
thermostat or network setpoint now starting the compressor.
NOTICE
To prevent compressor cycling and all compressors from starting up together
after loss of power, the required minimum on/off time default is 300 seconds
plus the random restart of 0 to 60 seconds. This may cause the compressor
time delay to be longer than indicated above.
NOTICE
For a unit with both water side economizer and hot gas reheat, Y3 from the
thermostat will be wired to W4 on the MT2310 I/O expansion module.
Unit Status
Unoccupied Operation – Stand Alone
Thermostat Control
The board will be in unoccupied mode if the unoccupied terminal
(U) is grounded.
LED Activity Type Color Description
5 Flash Mode Green Unoccupied Mode Active
Figure 8: Terminal “U” - Grounded for Unoccupied
E - Emer Shtdn Input
Ground
U - Unoccupied
Ground
LED
LED
FM
FM
SP
SP
RM
RM
GND
GND
LED
LED
FM
FM
SP
SP
RM
RM
GND
GND
TB3
TB3
E
E
E
E
U
U
U
U
LED
LED
FM
FM
SP
SP
RM
RM
GND
GND
LED
LED
FM
FM
SP
SP
RM
RM
GND
GND
TB3
TB3
E
E
E
E
U
U
U
U
Remote Shutdown
LED Activity Type Color Description
Rapid Flash Mode Green Emergency Shutdown
When the TB3-E terminal is grounded, the MT2300 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 9: Terminal “E” - grounded for remote shutdown
E - Emer Shtdn Input
Ground
U - Unoccupied
Ground
LED
LED
FM
FM
SP
SP
RM
RM
GND
GND
LED
LED
FM
FM
SP
SP
RM
RM
GND
GND
TB3
TB3
E
E
E
E
U
U
U
U
LEDLED FMFM SPSP RMRM GNDGND LEDLED FMFM SPSP RMRM GNDGND
TB3TB3
EE EE
UU UU
When in remote shutdown (E terminal grounded), control inputs
have no a󰀨ect upon unit operation. No faults or modes have
higher priority than remote shutdown. Remote shutdown and
brownout condition have the same level of priority. See Table 6
on page 16.
When the unit is in remote shutdown mode, the following occurs:
1. The compressor de-energizes (if enabled).
2. The fan de-energizes (if enabled).
3. Fault terminal (ALM) will remain de-energizes because
emergency shutdown is a “mode.”
When the E terminal is no longer grounded the unit will
automatically return to normal operation.
NOTICE
The remote shutdown input (E) will suspend unit operation. Disconnect power
when servicing the unit/controller.