Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 57

MM
4
6
A1
A2
MM
MM
3
2
1
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 OFC 1,2 CONDFAN1,2 2
Stage 2B OFC 3,4 CONDFAN3,4 2
LEGEND
MM — Motormaster ® Control
OFC — Outdoor Fan Contactor
OFM — Outdoor Fan Motor
B3
Circuit B
Coils
B2
B1
Circuit A
Coils
OFM(s) Logic
Controlled
OFM 1 See Table
OFM 3 See Table
See Table
OFM 6
OFM 4 See Table
Fans ON Ckt A # Fans ON Ckt B # Fans ON
Ckt A on. Stage up by individual circuit when SCTA > SCT_MAX
OFM1 1 0
OFM6 0 1 Ckt Bon. Stage up by individual circuit when SCTB > SCT_MAX
OFM1,3 2 0 Stage up by individual circuit when SCTA/B > SCT_MAX
Stage down by individual circuit when SCTA/B < SCT_MIN
OFM4,6 0 2
Fig. 6 — 75-Ton Standard Efficiency Unit Condenser Fan Staging Sequence
Applicable Units
Tonnage Efficiency
75 Standard
Staging Logic
Stage up to Stage 2A when SCTA>SCT_MAX
Stage up to Stage 2B when SCTB>SCT_MAX Stage down, OFC3 off, when Ckt B goes off.
Stage Up Logic Stage Down Logic
Stage down, OFC1 off, when Ckt A goes off.
Stage down to Stage 1A when SCTA< SCT_MIN
Stage down to Stage 1B when SCTB < SCT_MIN