Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 58

A1
MM
4
6
5
A2
A3
MM
3 1
2
A4
POWER
BOX
Controlling Output Contactor
Circuit Software Board Conrolled
A CONDFAN1 MBB Rly 6 OFC1
A CONDFAN2 MBB Rly 5 OFC2
B CONDFAN3 RCB Rly 1 OFC3
B CONDFAN4 RCB Rly 2 OFC4
Common,
M.M.=YES
or NO Contactor Software Pts # of Fans ON
Stage 1A OFC1 CONDFAN1 1
Stage 1B OFC3 CONDFAN3 1
Stage 2A OFC2 CONDFAN2 2
Stage 2B OFC4 CONDFAN4 2
Stage 3A OFC1,2 CONDFAN1,2 3
Stage 3B OFC3,4 CONDFAN3,4 3
LEGEND
MM — Motormaster ® Control
OFC — Outdoor Fan Contactor
OFM — Outdoor Fan Motor
Fig. 7 — 75-Ton High Efficiency and 90 to 120-Ton Standard Efficiency Unit Condenser Fan Staging Sequence
B4
Circuit B
Coils
B3
B2
Circuit A
Coils
B1
OFM(s)
Controlled Logic
OFM2 See Table
OFM 1,3 See Table
OFM5 See Table
OFM 4,6 See Table
Fans ON Ckt A # Fans ON Ckt B # Fans ON
Ckt A on. Stage up by individual circuit when SCTA > SCT_MAX Stage up to Stage 2A when SCTA>SCT_MAX
OFM2 1 0
Ckt Bon. Stage up by individual circuit when SCTB > SCT_MAX
OFM5 0 1
OFM1,3 2 0 Stage up by individual circuit when SCTA/B > SCT_MAX
OFM4,6 0 2 Stage down by individual circuit when SCTA/B < SCT_MIN
OFM1,2,3 3 0 Stage up & down by individual circuit
OFM4,5,6 0 3 Up if SCTA/B > SCT_MAX, Down if SCTA/B<SCT_MIN
Applicable Units
Tonnage Efficiency
75 High
90 Standard
105 Standard
120 Standard
Staging Logic
Stage up to Stage 2B when SCTB>SCT_MAX
Stage up to Stage 3A when SCTA>SCT_MAX
Stage up to Stage 3B when SCTB>SCT_MAX
Stage Up Logic Stage Down Logic
Stage down, OFC1 off, when Ckt A goes off.
Stage down, OFC3 off, when Ckt B goes off.
Stage down to Stage 1A when SCTA< SCT_MIN
Stage down to Stage 1B when SCTB < SCT_MIN
Stage down to Stage 2A when SCTA<SCT_MIN
Stage down to Stage 2B when SCTB<SCT_MIN