HP (Hewlett-Packard) H4H3 ユーザーズマニュアル

t Diagnostics (some models)

Green LED is not on, module
does not power up

Determine if both R and C module terminals are connected. Verify voltage is
present at module's R and C terminals.

Green LED intermittent,  mod‐
ule powers up only when com‐
pressor runs

Determine if R and Y terminals are wired in reverse. Verify module's R and C ter‐
minals have a constant source.

TRIP LED is on but system
and compressor check OK

Verify Y terminal is wired properly per OEM wiring diagram. Verify voltage at con‐
tactor coil falls below 0.5VAC when off.  Verify 24VAC is present across Y and C
when thermostat demand signal is present. If not, R and C are reverse wired.

TRIP LED and ALERT LED
flashing together

Verify R and C terminals are supplied with 19-28VAC.

ALERT Flash Code 3
(Compressor short cycling)
displayed incorrectly

Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at
contactor coil falls below 0.5VAC when off.

ALERT Flash Code 5 or 6
(Open Circuit, Missing Phase)
displayed incorrectly

Check that compressor T1 and T3 wires are through module's current sensing
holes. Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at
contactor coil falls below 0.5VAC when off.

ALERT Flash Code 8
(Welded Contactor) displayed
incorrectly

Determine if module's Y terminal is connected. Verify Y terminal is connected to
24VAC at contactor coil. Verify 24VAC is present across Y and C when        ther‐
mostat demand signal is present. If not, R and C are reversed wired. Verify
voltage at contactor coil falls below 0.5VAC when off. Review.

• R-410A refrigerant operates at 50% - 70% higher pressures than R-22.  Be sure that servicing equipment and

replacement components are designed to operate with R-410A.

• R-410A refrigerant cylinders are rose colored.
• Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
• R-410A systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose.
• Manifold sets should be 750 psig high-side and 200 psig low-side with 520 psig low-side retard.
• Use hoses with 750 psig service pressure rating.
• Leak detectors should be designed to detect HFC refrigerant.
• R-410A, as with other HFC refrigerants, is only compatible with POE oils.
• POE oils absorb moisture rapidly.  Do not expose oil to atmosphere.
• POE oils may cause damage to certain plastics and roofing materials.
• Vacuum pumps will not remove moisture from oil.
• A liquid line filter-drier is required on every unit.
• Do not use liquid line filter-driers with rated working pressures less than 600 psig.
• Do not install a suction line filter-drier in liquid line.
• Wrap all filter-driers and service valves with wet cloth when brazing.
• Do not use with an R-22 TXV.
• If indoor unit is equipped with an R-22 TXV, it must be changed to an R-410A TXV.
• Do not use capillary tube indoor coils.
• Never open system to atmosphere while it is under a vacuum.
• When system must be opened for service, break vacuum with dry nitrogen and replace all filter-driers.
• Do not vent R-410A into the atmosphere.
• Observe all WARNINGS, CAUTIONS, NOTES, and bold text.

International Comfort Products, LLC

Lewisburg, TN 37091

International Comfort Products, LLC

Lewisburg, TN 37091