Carrier WEATHERMAKER 48A2020 - Page 49

49
WITH MOTORMASTER OPTION
20-35 Ton
Contactor OFM(s)
Software Board Conrolled Controlled
Common MM_A_RUN SCB Relay 1 n/a OFM1 Any compressor ON, speed via MM_A_VFD
Common CONDFANB MBB Rly 5 OFC2 OFM2
# of Fans ON
Fans ON # of Fans ON Fans ON
Stage 1 MM1 1 OFM1 Stage 1 MM1 1 OFM1
Stage 2 MM1, OFC2 2 OFM1,2 Stage 2 MM1, OFC2 2 OFM1,2
Stages 1 and 2 start with MM_A_VFD at 50%, then modulates to control HP setpoint
Stage 2 if OAT > 75
Stage 2 if SCTA or STCB > HPSP
Stage down if SCTA/B < HPSP - 40 for two minutes and OAT < 73
Stage down starts with MM_A_VFD at 50%, then modulates to control HP setpoint
WITH MOTORMASTER OPTION
40-50 Ton
Contactor OFM(s)
Software Board Conrolled Controlled
Common
MM_A_RUN SCB Relay 1 n/a OFM1,2
Common CONDFANB MBB Rly 5 OFC2 OFM3,4
# of Fans ON
Fans ON # of Fans ON Fans ON
Stage 1 MM1,2 2 OFM1,2 Stage 1 MM1,2 2 OFM1,2
Stage 2 MM1,2, OFC2 4 OFM1,2,3,4 Stage 2 MM1,2, OFC2 4 OFM1,2,3,4
Stages 1 & 2 start with MM_A_VFD at 50%, then modulates to control HP setpoint
Stage 2 if OAT > 75
Stage 2 if SCTA or STCB > HPSP
Stage down if SCTA/B < HPSP - 40 for two minutes and OAT < 73
Stage down starts with MM_A_VFD at 50%, then modulates to control HP setpoint
WITH MOTORMASTER OPTION
60 Ton RTPF
Contactor OFM(s)
Software Board Conrolled Controlled
Common
MM_A_RUN SCB Relay 1 n/a OFM1,2
Common CONDFANB MBB Rly 5 OFC2 OFM3,4,5,6
# of Fans ON
Fans ON # of Fans ON Fans ON
Stage 1 MM1,2 2 OFM1,2 Stage 1 MM1,2 2 OFM1,2
Stage 2 MM1,2,OFC2 6 OFM1,2,3,4,5,6 Stage 2 MM1,2,OFC2 6
O
FM1,2,3,4,5,6
Stage 2 starts with MM_A_VFD at 50%, then modulates to control HP setpoint
Stage 2 if OAT > 75
Stage 2 if SCTA or STCB > HPSP
Stage down if SCTA/B < HPSP - 40 for two minutes and OAT < 73
Stage down starts with MM_A_VFD at 50%, then modulates to control HP setpoint
WITH MOTORMASTER OPTION
60 Ton MCHX
Contactor OFM(s)
Software Board Conrolled Controlled
A CONDFANA MBB Rly 6 OFC4 OFM4
A MM_A_RUN SCB Relay 1 n/a OFM3
B CONDFANB MBB Rly 5 OFC2 OFM2
B MM_B_RUN SCB Relay 2 n/a OFM1
# of Fans ON
Fans ON # of Fans ON Fans ON
Stage 1 MM3 1 OFM3 Stage 1 MM1 1 OFM1
Stage 2 MM3, OFC4 2 OFM3,4 Stage 2 MM1, OFC2 2 OFM1,2
Stage 2 starts with MM_A_VFD / MM_B_VFD at 50%, then modulates to control HP setpoint
Stage down starts with MM_A_VFD at 50%, then modulates to control HP setpoint
LogicCircuit
Controlling Output
Circuit A
Circuit B
If either of the SCT sensors has failed, then the control defaults to control based on the OAT sensor and turns on
CONDFANB when the ambient is above 65 dF and off when the ambient temperature is below 50 dF. If the SCT and OAT
sensors have all failed then the control turns on CONDFANB when any compressor is on.
Circuit
Controlling Output
Logic
Any compressor ON, speed via MM_A_VFD
Circuit A
Circuit B
If either of the SCT sensors has failed, then the control defaults to control based on the OAT sensor and turns on
CONDFANB when the ambient is above 65 dF and off when the ambient temperature is below 50 dF. If the SCT and OAT
sensors have all failed then the control turns on CONDFANB when any compressor is on.
Circuit
Controlling Output
Logic
Any Compressor ON, speed via MM_A_VFD
Circuit A
Circuit B
If either of the SCT sensors has failed, then the control defaults to control based on the OAT sensor and turns on
CONDFANB when the ambient is above 65 dF and off when the ambient temperature is below 50 dF. If the SCT and OAT
sensors have all failed then the control turns on CONDFANB when any compressor is on.
Circuit
Controlling Output
Logic
Comp A1 or A2 ON, speed Via MM_A_VFD
Comp B1 or B2 ON, speed Via MM_B_VFD
Circuit A
Circuit B
If the SCTB sensor has failed, then the control defaults to control based on the OAT sensor and turns on CONDFANB when
the ambient is above 65 dF and off when the ambient temperature is below 50 dF. If the SCTB and OAT sensors have all
failed then the control turns on CONDFANB when any compressor is on.
Stage up occurs if SCTA > HPSP or OAT > 75 Stage up occurs if SCTB > HPSP or OAT > 75
g
OAT < 73
g
OAT < 73
If the SCTA sensor has failed, then the control defaults to control based on the OAT sensor and turns on CONDFANA when
the ambient is above 65 dF and off when the ambient temperature is below 50 dF. If the SCTA and OAT sensors have all
failed then the control turns on CONDFANA when any compressor is on.
MM
1
2
MM
1
4
MM
2
3
4
MM
1
MM
2
3
6
5
MM
3
MM
1
2
4
Fig. 9 — Outdoor Fan Staging Sequence for Factory-Installed Motormaster Option Units