OM 1263 • MICROTECH UNIT CONTROLLER 28 www .DaikinApplied .com
Commission Unit
IRT
(Heat Pump only) is a status only item which displays the
current indoor refrigerant temperature sensor reading .
ORT
(Heat Pump only) is a status only item which displays the
current outdoor refrigerant temperature sensor reading .
SSH DB
is an adjustable item that sets deadband around
the Eff SSH Spt for superheat control of either the indoor
expansion valve (cooling operation) or outdoor expansion valve
(EVO) .
SSH Lo Base
is an adjustable item that sets a low limit for
the EffSH Base value. This parameter is for test purposes and
should not generally be changed in the field.
SSH Hi Base
is an adjustable item that sets a high limit for
the EffSH Base value. This parameter is for test purposes and
should not generally be changed in the field.
Htg EVI Method
(Heat Pump only) is an adjustable item
that sets the method of control of the indoor expansion valve
(EVI) during heating operation . If set to “STD” EVI is driven
continuously to 100% open during heating operation . If set to
subcooling “Sbc” then EVI is control to maintain the Eff SC Spt
during heating operation .
IC SC Spt
is an adjustable item that sets a base value for the
Eff SC Spt during heating operation.
IC SC DB
is an adjustable item that sets a deadband around
the Eff SC Spt during heating operation.
HtgSC EVI Min=
is an adjustable item which sets a minimum
indoor expansion valve position for steady-state sub cooling
reset control during heat pump heating operation .
Clg EVO Method
(Heat Pump only) is an adjustable item that
sets the method of control of the outdoor expansion valve
(EVO) during cooling operation . If set to “STD” EVO is driven
continuously to 100% open during cooling operation . If set to
“Sbc” then EVO is control to maintain the Eff SC Spt during
cooling operation .
OC SC Spt
is an adjustable item that sets a base value for the
Eff SC Spt during cooling operation.
OC SC DB
is an adjustable item that sets a deadband around
the Eff SC Spt during cooling operation.
ClgSC EVO Min=
is an adjustable item which sets a minimum
outdoor expansion valve position for steady-state sub cooling
reset control during heat pump cooling operation .
ManCtrl EV Op
is an adjustable item that sets the mode of
expansion valve control during Manual Control operation .
If set to “Auto” the expansion values are automatically
controlled during Manual Control operation . If set to “Man”
the expansion valves are manually controlled during Manual
Control operation .
Expansion Valve Control (EVI or EVO, EVO supplied only
on heat pumps)
The EVI valve is modulated use a PI Loop during cooling
operation to maintain the effective suction superheat set point.
On heat pump units EVI is either driven to the 100% open
position or modulated to maintain the effective subcooling set
point during heating operation .
The EVO valve is modulated use a PI Loop during heating
operation to maintain the effective suction superheat set
point . EVO is either driven to the 100% open position or
modulated to maintain the effective subcooling set point
during cooling operation .