CAUTION
!
Risk of Electric Shock.
Disconnect electric power
to system until installation
is complete. Do not use on
circuit exceeding specified
voltage. Higher voltage will
damage control and could
cause shock or fire hazard.
This control is not intended
for use in locations where
it may come in contact with
water.
May cause flame rollout.
Shut off main gas to heating
system until installation is
complete.
21V51D-751
Two-Stage Integrated Furnace Control for PSC,
Variable Speed, and ECMx Blower Motors
INSTALLATION INSTRUCTIONS
FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY BEFORE
INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL
INJURY AND/OR PROPERTY DAMAGE.
DESCRIPTION
SPECIFICATIONS
PARTS INCLUDED
The 21V51D-751 is a Two-Stage HSI Integrated Furnace
Control kit for many Carrier and ICP equipment brands with
PSC, Variable Speed, and ECMx Blowers configured via
dipswitch selection.
The kit contains:
• 50V51-751 Integrated Furnace Control with Mounting Tray
• 3 Harness Assemblies
• Control Label
• 8 Wire Nuts
• Installation Instructions
white-rodgers.com
emerson.com
PART NO. 37-7625001
1711
TWINNING: 21V51D-751 CANNOT be twinned with
any Carrier, ICP, or ICM brand controls. Both control
boards must be from the same manufacturer for proper
functionality.
ELECTRICAL RATINGS:
Input Voltage:
18 to 30 VAC, 60 Hz
Current:
0.8 amp @ 25 VAC
Relay Contact Ratings:
Gas Valve 1st Stage: 1.5 A 0.6 PF @ 30 VAC
Gas Valve 2nd Stage: 0.5 A @ 30 VAC
Ignitor Relay: 2.0 A @ 120 VAC
Inducer Relay: 2.2 A FLA @ 120 VAC
Inducer Relay: 3.5 A LRA @ 120 VAC
PSC Circulator Relay: 14.5 A FLA @ 120 VAC
PSC Circulator Relay: 25 A LRA @ 120 VAC
ECMx Circulator Relay: 4.0 mA RMS @ 18 VAC
ECMx Circulator Relay: 12.0 mA RMS @ 30 VAC
Humidifier Load: 1.0 A @ 120 VAC
Electronic Air Cleaner: 1.0 A @ 120 VAC
Flame Current Requirements:
Min current to insure flame detection: 0.25 μA DC*
Max current for non-detection: 0.1 μA DC
Max allowable leakage resistance: 150 M ohms
* Measuring with a DC voltmeter (1VDC = 1 μA)
OPERATING TEMPERATURE RANGE:
-40° to 175°F (-40° to 80°C)
HUMIDITY RANGE:
5 to 95% relative humidity (non-condensing)
AGENCY APPROVALS:
CSA USA / Canada
GASES APPROVED:
Natural, Manufactured, Mixed,
Liquid Petroleum, and LP Gas Air Mixtures.
