Carrier SINGLE PACKAGE ROOFTOP UNITS ELECTRIC COOLING/GAS HEATING EY024-048 - Manual (Page 61)

Tables 24-26 show the input and output channel
designations.
Table 24 — I/O Channel Designations Base Module — CV
TERMINAL NO. ASSIGNMENT TERMINAL NO. ASSIGNMENT
T1-2 SPT (CCN) — 10K ⍀ Thermistor T23-25 Compressor 2 Safety — DI (24 vac)
T3-4 STO (CCN) — 10K ⍀ Thermistor T24-25 Outside Air Enthalpy — DI (24 vac)
T5-6 OAT — 5K ⍀ Thermistor T26-27 Economizer Pos. — AO (4-20 mA)
T7-8 SAT — 5K ⍀ Thermistor T28-29 Heat 1 Relay — DO (24 vac)
T9-10 — T30-29 Heat 2 Relay — DO (24 vac)
T11-12 SAT Reset — AI (4 to 20 mA) T31-32 CV Power Exhaust 1/Modulating Power Exhaust — DO (115 vac)
T13-14 — T33-32 CV Power Exhaust 2 — DO (115 vac)
T15-16 — T34-35 Condenser Fan — DO (115 vac)
T17-25 Y1 or Remote Start/Stop — DI (24 vac) T36-35 OFC2 — DO (115 vac)
T18-25 Y2 — DI (24 vac) T37-38 —
T19-25 W1 — DI (24 vac) T39-38 —
T20-25 W2 — DI (24 vac) K1 Indoor Fan Relay — DO (LV)
T21-25 G — DI (24 vac) K2 Compr. 1 — DO (HV)
T22-25 Compressor 1 Safety — DI (24 vac) K3 Compr. 2 — DO (HV)
Table 25 — I/O Channel Designations Base Module — VAV
TERMINAL NO. ASSIGNMENT TERMINAL NO. ASSIGNMENT
T1-2 SPT (CCN) — 10K ⍀ Thermistor T23-25 Compressor 2 Safety — DI (24 vac)
T3-4 RAT — 5K ⍀ Thermistor T24-25 Outside Air Enthalpy — DI (24 vac)
T5-6 OAT — 5K ⍀ Thermistor T26-27 Economizer Pos. — AO (4-20 mA)
T7-8 SAT — 5K ⍀ Thermistor T28-29 Heat 1 Relay − DO (24 vac)
T9-10 — T30-29 Heat Interlock Relay — DO (24 vac)
T11-12 SAT Reset — AI (4 to 20 mA) T31-32 Modulated Power Exhaust — DO (115 vac)
T13-14 — T33-32 —
T15-16 — T34-35 Condenser Fan — DO (115 vac)
T17-25 Remote Start/Stop — DI (24 vac) T36-35 OFC2 — DO (115 vac)
T18-25 — T37-38 Unloader 1 — DO (115 vac)
T19-25 — T39-38 Unloader 2 — DO (115 vac)
T20-25 — K1 Indoor Fan Relay — DO (LV)
T21-25 — K2 Compr. 1 (HV)
T22-25 Compressor 1 Safety — DI (24 vac) K3 Compr. 2 — DO (HV)
Table 26 — I/O Channel Designations Expansion Module (Field-Installed) — CV and VAV
TERMINAL NO. ASSIGNMENT TERMINAL NO. ASSIGNMENT
T1-2 — T23-25 Fire — Evacuation — DI (24 vac)
T3-4 — T24-25 Fire — Smoke Purge — DI (24 vac)
T5-6 — T26-27 —
T7-8 — T28-29 —
T9-10 — T30-29 Alarm Light Indicator — DO (24 vac)
T11-12 IAQ Indoor — AI (4 to 20 mA) T31-32 Power Exhaust Fire No. 1 — DO (115 vac)
T13-14 IAQ Outdoor — AI (4 to 20 mA) T33-32 Power Exhaust Fire No. 2 — DO (115 vac)
T15-16 — T34-35 Power Exhaust Fire No. 3 — DO (115 vac)
T17-25 Fan Status — DI (24 vac) T36-35 Power Exhaust Fire No. 4 — DO (115 vac)
T18-25 Filter Status − DI (24 vac) T37-38 —
T19-25 Field Applied Status — DI (24 vac) T39-38 —
T20-25 Demand Limit — DI (24 vac) K1 —
T21-25 Fire — Unit Shutdown — DI (24 vac) K2 —
T22-25 Fire — Pressurization — DI (24 vac) K3 —
LEGEND (Tables 24-26)
AI — Analog Input
AO — Analog Output
CCN — Carrier Comfort Network
CV
— Constant Volume
DI — Direct Input
DO — Direct Output
HV — High Voltage
IAQ — Indoor Air Quality
K ⍀ — Kilo-Ohms
LV — Low Voltage
OAT — Outdoor-Air Temperature
OFC — Outdoor Fan Contactor
RAT — Return-Air Temperature
SAT
— Supply-Air Temperature
SPT — Space Temperature
STO — Space Temperature Offset
T
— Terminal
VAV — Variable Air Volume
NOTE: For 4 to 20 mA signals, all even numbered terminals are negative (−) polarity, and all odd numbered terminals are positive (+) polarity.
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