Daikin MicroTech MT2300 - Operation; Start-Up; Fan Speed Selection; Bacnet Communication Module

OPERATION
MICROTECH 2300 UNIT CONTROLLERDAIKIN APPLIED
10
Operation
Start-Up
The MT2300 unit controller’s valve or pump request terminal [IV/
PR (H6)] is an output signal to external devices to allow water
ow as required by the heat pump. The IV/PR (H6) terminal
follows compressor operation inversely if connected to the
normally open terminal and simultaneously when connected to
the normally closed terminal. The IV/PR (H6) terminal can be
used as a signal to an external pump or valve to enable ow to
the unit. The compressor start is delayed for 60 seconds after the
IV/PR (H6) output is energized.
Table 5: IV/PR(H6) terminal and compressor operation
IV/PR(H6) Compressor On Compressor O󰀨
Normally Open 24 VAC 0 VAC
Normally Closed 0 VAC 24 VAC
Fan Speed Selection
The SW1-SW4 conguration switches on the MT2310 I/O
expansion module allow CFM settings to be eld adjustable with
some fan options. Fan speed control optimizes unit fan speed
based on thermostat/room sensor inputs.
The variable speed fan conguration switches allow for
manually setting an optimal fan speed specic to the application
requirements. The four primary speed proles are selected using
SW1 and SW2. SW3 reduces the heating and cooling speeds
by 15%, and the SW4 switch selects the fan speed when in Fan
Only mode (subject to the operational rules below).
Fan Only SW4
OFF = 20%
ON = Cool Stage 1 speed (Does not a󰀨ect heat or cool mode fan
speeds)
General Fan Operation Rules
50% minimum whenever heating or cooling
100% for Auxiliary Electric Heat
Hydronic heating/cooling = Heat Stage 1/Cool Stage 1
DEHUM = Cool Stage 1 minus 10% (50% minimum)
Table 6: I/O Expansion Module Conguration Switch
Fan
Speed
Row
Switch
1
Switch
2
Switch
3
Fan
Only
1
Cool
Stage
1
Cool
Stage
2
Heat
Stage
1
Heat
Stage
2
1 OFF OFF OFF 20% 80% 100% 80% 100%
2 ON OFF OFF 20% 70% 90% 70% 90%
3 OFF ON OFF 20% 60% 80% 60% 80%
4 ON ON OFF 20% 50% 70% 50% 70%
5 OFF OFF ON 20% 65% 85% 65% 85%
6 ON OFF ON 20% 55% 75% 55% 75%
7 OFF ON ON 20% 50% 65% 50% 65%
8 ON ON ON 20% 50% 55% 50% 55%
1
See “Fan Only SW4” section above.
NOTE: Refer to Figure 3 for conguration switch location.
BACnet Communication Module
On units with an optional BACnet communication module, fan
speeds can be set through network communications to 1%
resolution of duty cycle. For hydronic or compressorized modes,
the range is 50-100%, and for fan only mode, the range is
10-100%. When enabled, the network fan speed settings will
override the local conguration switches. When the MT2310
status LED interval is yellow instead of O󰀨, this indicates that the
network is overriding the fan speed settings.
Sequence Of Operation
Fan Only
On a call for fan the fan starts immediately through the activation
of the Thermostat G terminal or Room Sensor Fan Switch.
LED Activity Type Color Description
1 Flash Mode Green
No Call for Heating/Cooling/
Dehumidication
4 Flash Mode Green Call for Fan Only
NOTE: If conguration switch SW2 on the main control board is OFF the fan will
run continuous whenever there is a power supply to the unit. For cycling
fan operation conguration swithc SW2 needs to be on.
Cooling
LED Activity Type Color Description
1 Flash Mode Green
No Call for Heating/Cooling/
Dehumidication
2 Flash Mode Green Call for Cooling
The compressor minimum o󰀨 timer, and random start timer must
expire before the compressor will be energized. On a call for
1st stage cooling from a thermostat or network setpoint, the H6
output on the MT2300 board is activated to open the motorized
valve to allow water ow through the heat exchanger. The fan
starts immediately (unless it is already on through activation
of the G terminal by the thermostat fan switch “ON” or a wall
sensor command) at “FAN ONLY” setting. The compressor starts
after 60 seconds to make sure the motorized valve has fully
open for proof of water ow and the fan CFM output increases.
The compressor minimum on timer of 180 seconds starts. The
reversing valve will de-energize 5 seconds after the compressor
starts. The fan CFM output is now determined by the MT2310 I/O