46
WITHOUT MOTORMASTER OPTION
36-50 Ton
Contactor
OFM(s)
Software
Board
Conrolled
Controlled
Common
CONDFANA
MBB Rly 6
OFC1
OFM1,2
Common
CONDFANB
MBB Rly 5
OFC2
OFM3,4
# of Fans ON
Fans ON
# of Fans ON
Fans ON
Stage 1
OFC1
2
OFM1,2
Stage 1
OFC1
2
OFM1,2
Stage 2
OFC1,2
4
OFM1,2,3,4
Stage 2
OFC1,2
4
OFM1,2,3,4
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
WITH MOTORMASTER OPTION
36-50 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
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
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 A
Circuit B
Circuit
Controlling Output
Logic
Any compressor ON
MM
1
4
MM
2
3
WITHOUT MOTORMASTER OPTION
50 Ton, 60 Ton RTPF
Contactor
OFM(s)
Software
Board
Conrolled
Controlled
Common
CONDFANA
MBB Rly 6
OFC1
OFM1,2
Common
CONDFANB
MBB Rly 5
OFC2
OFM3,4,5,6
# of Fans ON
Fans ON
# of Fans ON
Fans ON
Stage 1
OFC1
2
OFM1,2
Stage 1
OFC1
2
OFM1,2
Stage 2
OFC2
4
OFM3,4,5,6
Stage 2
OFC2
4
OFM3,4,5,6
Stage 3
OFC1,2
6
OFM1,2,3,4,5,6
Stage 3
OFC1,2
6
OFM1,2,3,4,5,6
Stage 3 if OAT > 75
Stage 3 if SCTA or STCB > HPSP
Stage down if SCTA/B < HPSP - 40 for two minutes and OAT < 73 (stage 2 can only occur when staging down)
WITH MOTORMASTER OPTION
50 Ton, 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
OFM1,2,3,4,5,6
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
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
Any Compressor ON
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
Circuit A
Circuit B
4
MM
1
MM
2
3
6
5
Fig. 9 — Outdoor Fan Staging Sequence (cont)
Summary of Contents for Carrier Weathermaker 48A2
Page 105: ...105 Fig 20 Typical Main Control Box Wiring Schematic 48 50A2 A3 A4 A5 Units...
Page 106: ...106 Fig 21 Typical Auxiliary Control Box Wiring Schematic...
Page 107: ...107 Fig 22 Typical 2 Stage Gas Heat Wiring Schematic Size 060 Units Shown a48 8357...
Page 108: ...108 TO NEXT PAGE Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown A48 7296...
Page 109: ...109 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown cont A48 8358...
Page 110: ...110 Fig 24 Typical Electric Heat Control Schematic 50 Series Size 060 Units Shown a50 8228...
Page 111: ...111 Fig 25 Typical Power Schematic 48 50A2 A3 A4 A5 060 Unit Shown...
Page 112: ...112 Fig 26 Typical Low Ambient Controls Option Wiring...
Page 113: ...113 Fig 27 Typical Small Chassis Component Location Size 020 035 Units...
Page 114: ...114 Fig 28 Typical Large Chassis Component Locations Size 040 060 Units...
Page 118: ...118 Fig 30 Economizer Control Board ECB1 and VAV Control Board ECB2 A48 7706...
Page 142: ...142 A48 3733 Fig 56 Main Burner Removal...
Page 176: ...176 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716...
