Specifications

Page 28 of 36 / IM 1049-4
Figure 42: Multiple Unit Control Panel and Board
Themultipleunitcontrolboardprovidesthecomponents
necessary to protect the MicroTech III unit controller from
electricaldamagethatmayoccurwhenusingstandardoff-
the-shelfrelays.
Donotusetheunoccupied(U-terminal)featurewiththemul-
tipleunitcontrolboard.
Figure 43: Wiring Multiple Unit Control Board (MUCP)
Multiple Unit Control Panel
Circuit Board
MicroTech III Unit Control Board
Low Voltage Terminal Strip
C
G
Y1
Y2W1
W2
A
R
O
Thermostat Terminals
W1
Y1
W2
Y2
G
-
C
+
R
RYGW
RYGW
RYGW
RYGWC
K3
K2
K1
TB3
TB4
TB2
TB1
C
G
Y1
Y2W1
W2
A
R
O
C
G
Y1
Y2W1
W2
A
R
O
TB2 - Unit #1
TB2 - Unit #2
TB2 - Unit #3
Notes: Dottedlinesrepresentlowvoltage(ClassII)wiring;a
color-coded thermostat cable is recommended.
 MUCPmaybemountedhorizontallyorverticallyon
heat pump cabinet or any convenient surface.
Do not use if using night setback.
Thermostat must be A.C. voltage
Additional Accessories – General
Motorized Isolation Valve & Relay
Themotorizedvalvekitisavailableasafactory-installedand
wiredoptionormaybeorderedasaeld-installedaccessory.
Wired as shown in Figure 41,themotorizedvalvewillopen
onacallforcompressoroperation.Valvesforunitsizes007
to019are1/2"whileunitsizes024to060are3/4".
UsingaNormallyClosed(N/C),poweropenvalve,wireas
illustrated in Figure 41.
Figure 41: Normally Closed, Power Open Motorized Valve
Actuator &
Valve Assembly
Anti-short Bushing
Connector
Conduit
Pin(s), female
connect to terminal H8
Connector
Anti-short
Bushing
Note: Connectors on valve must be cut off and stripped back
andthewirestwistedtomakeconnectionstotheIV/
PRTerminals
Pump Restart Relay Kit P/N 061419001
The MicroTech III unit controller has an internal Pump
Restart Relay connected to H8, Pin 2 for the Normally Open
(N/O)terminaloftheinternalrelay.
ConnecttoH8,Pin1fortheNormallyClosed(N/C)terminal
of the internal relay.
Theoutputoftheinternalpumprestartrelayis24-voltsAC
andtheoutputisnotavailablewhentheH8connectionis
usedtocontrolamotorizedvalve.
Multiple Unit Control (up to 3 units) (P/N 056794201)
Themultipleunitcontrolboardisanaccessoryusedwhenup
to3-unitsarecontrolledfromasinglethermostat.Typically
thecontrolpanelandboardiscentrallymountedbetweenthe
unitsandthermostat.Amaximumof2boardsmaybeused
togetherifupto6-unitsmustbeconnectedandcontrolled
from a single thermostat. For detailed installation instructions
refer to IM 952.
ThisversionofthecontrolusesVACrelaysandshouldnotbe
usedincombinationwithanyotheraccessoriesorequipment
that require VDC connections.