Carrier WeatherExpert 48N2 - Page 59

59
Circuit B Coils
120 Ton Standard Efficiency (identical to 75 Ton High Efficiency)
Contactor OFM(s)
Software Board Conrolled Controlled
A CONDFAN1 MBB Rly 6 OFC1 OFM2 B CONDFAN2 MBB Rly 5 OFC2 OFM5
Common CONDFAN3 RCB Rly 1 OFC3 OFM1,6 Common CONDFAN4 RCB Rly 2 OFC4 OFM3,4
# of Fans ON
Fans ON # of Fans ON Fans ON
Stage 1 OFC1 1 OFM2 Stage 1 OFC2 1 OFM5 Stage 2 OFC1,3 2 OFM1,2,6 Stage 2 OFC2,3 2 OFM1,5,6
Circuit A Stage 3 OFC1,3,4 3 OFM1,2,3,4,6 Stage 3 OFC2,3,4 3 OFM1,3,4,5,6 Coils
Low Ambient Prestart 1 (OAT ≤ 50 F) = Stage 1 Low Ambient Prestart 2 (50 F < OAT < 70 F) = Stage 2 High Ambient Prestart (OAT ≥ 70 F) = Stage 3 High Saturated Condensing Temp (SCT>130) = Stage 3
Stage down allowed if SCT<SCT_MIN Stage up allowed if SCT_MAX<SCT<130
Circuit B
Current stage if SCT_MIN<SCT<SCT_MAX
Coils
130 Ton Standard Efficiency 120-130 Ton High Efficiency (identical to 150 Ton Standard Efficiency)
Contactor OFM(s)
Software Board Conrolled Controlled
A CONDFAN1 MBB Rly 6 OFC1 OFM2
Common CONDFAN2 MBB Rly 5 OFC2 OFM5
B CONDFAN3 RCB Rly 1 OFC3 OFM8
Common CONDFAN4 RCB Rly 2 OFC4 OFM3,7 Common CONDFAN5 RCB Rly 3 OFC5 OFM1,4,6,9
Circuit A Coils
Circuit
Controlling Output
Logic
Circuit
Controlling Output
Logic
Comp A1, A2, A3, or A4 ON
Comp B1, B2, B3, or B4 ON
Circuit A or B SCT or OAT
Allow Fan Staging if OAT < 70 F and:
See 150 Ton Standard Efficiency
Circuit A or B SCT or OAT
Comp A1, A2, A3, or A4 ON
Comp B1, B2, B3, or B4 ON
Circuit A or B SCT or OAT
Circuit A or B SCT or OAT
Circuit A
Circuit B
Circuit A or B SCT or OAT
POWER BOX
3
MM
2
6
MM
5
A4
A3
B2
B1
B3
1
4
A2
POWER BOX
3
MM
2
9
MM
8
A4
A3
B2
B1
B3
1
7
6
5
4
B4
A2
A1
A1
B4
Fig. 12 — 120-130 Ton Unit Condenser Fan Staging Sequence
a48-8699
LEGEND
MM — Motormaster OAT — Outdoor Air Temperature OFC — Outdoor Fan Contactor OFM — Outdoor Fan Motor