506 01 2303 01
31
Specifications are subject to change without notice.
Table 9 – CHS Defrost Board I/O and Jumper Configurations
Inputs
Point Name
Type of I/O
Connection Pin Number
Unit Connection
Note
G Fan
DI, 24-vac
P2-3
Not used
Y1 Cool 1
DI, 24-vac
P2-5
TB-Y1
W1 Heat 1
DI, 24-vac
P2-7
TB-W1
Y2 Cool 2
DI, 24-vac
P2-4
TB-Y2
CHS****G/H only
R Power
24-vac
P3-1
TRAN2
C Common
24-vac, ground
P3-3
TRAN2
DFT1 Defrost Switch
DI, 24-vac
DFT-1 to DFT-1
DFB
DFT Jumper
DI, 24-vac
DFT-1 to DFT-2
CHS****G/H only
Outputs
Point Name
Type of I/O
Connection Pin Number
Unit Connection
Note
OF OD Fan
DO, 24-vac
OF
OFR
RVS1
DO, 24-vac
P3-7 to P3-5
RVS1
Energize in COOL
COMP 1
DO, 24-vac
P3-10
CADM1-Y
TB---W2
DO, 24-vac
E-HEAT
HC-1 (TB4-1)
COMP 2 / 2
nd
Stage
DO, 24-vac
P3---8
CADM2---Y/CADM1---Y2
CHS****G/H only
Configuration
Point Name
Type of I/O
Connection Pin Number
Unit Connection
Note
Select Jumper
24-vac
P1-1
1 Compressor
24-vac
P1-2
2 Compressor
24-vac
P1-3
CHS****G/H only
Speed-Up Configuration
Point Name
Type of I/O
Connection Pin Number
Unit Connection
Note
Speed-Up Jumper
JMP17
Speed-Up Jumper
JMP18
Jumper for 1-3 secs: Factory Test, defrost runs for 12 seconds or less
Jumper for 5-20 secs: Forced Defrost, defrost runs for 30 secs if DFT1 is open
DFB Power: 24-V at Pin P3-1, COM at P3-3 (required in all modes)
MODE
COOL
OFF After COOL
HEAT-1
HEAT-2
OFF After HEAT-1
DEFROST During HEAT
Inputs
Pin
Y1
P2-5
24-V
0-V
0-V
0-V
0-V
0
-V
W1
P2-7
0-V
0-V
24-V
24-V
0-V
24-V
DFT
DFT1-DFT1
OPEN
OPEN
Note 1
Note 1
Note 1
CLOSED
Outputs
Pin
OD Fans
OF
24-V
0-V
24-V
24-V
0-V
0-V
Rev Valve
P3-7
24-V
24-V
0-V
0-V
0-V
24-V
Compressor
P3-10
24-V
0-V
24-V
24-V
0-V
24-V
Electric Heat
E-HEAT
0-V
0-V
0-V
0-
V Note 2
0-V
24-V
W2
0-V
0-V
0-V
24-V
0-V
0
or 24-V
Notes:
1. DFT may be OPEN or CLOSED during Heat mode operation, depending on outdoor coil temperature. Defrost mode cannot start until Time window
opens in DFB Defrost mode logic.
2. Call for electric heat may originate at the space thermostat (space demand) or at the DFB during Defrost. Thermostat signal will also be present on
CHS’s W2 terminal and the DFB’s E---HEAT terminal.
3. Single Circuit, two stage units are configured as two compressor unit on the defrost board.
C11044
Fig. 24 -- Defrost Control Board (DFB) Location
