4. W-2WAY ECO-i Alarm Codes

W-2WAY ECO-i SYSTEM Trouble Diagnosis

H07 Alarm

 

 

Alarm code

H07

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alarm meaning

No-oil alarm

 

 

 

 

 

Alarm conditions

This alarm occurs when oil does not flow for a specified amount of time in tubing where oil

 

 

 

flow constantly. (The presence of oil is detected by a temperature sensor.)

 

 

 

Judgment method:

 

 

 

 

 

 

Tcal (calculated by the formula below from the oil temperature) is compared with the discharge

 

 

 

temperature. If Tcal is higher than the discharge temperature then oil is judged to be present.

 

 

 

If Tcal is lower than the discharge temperature, oil is judged to be not present.

 

 

 

Tcal={(0.0254 · T_oil · LP2 +0.0298 · T_oil · LP +0.8842 · T_oil –2.9953 · LP2 –11.091 · LP +436.94)

 

 

 

 

+2.9953 · HP2 +11.091 · HP –436.94}/(0.0254 · HP2 +0.0298 · HP +0.8842)

 

 

 

 

 

 

 

 

These points are calculated from the oil temperature and compared

 

 

 

 

 

 

 

 

with the discharge temperature

 

 

 

 

 

 

 

 

 

 

 

 

High pressure

 

 

 

 

ŽLower than the dis

 

 

 

 

 

 

 

 

 

ch

arge

 

Discharge

 

 

 

 

 

 

temperature: No oil

 

 

 

 

 

 

 

 

 

 

 

 

 

 

temperature

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Higher than the discharge

 

 

 

 

 

 

 

 

 

 

 

 

temperature: Oil present

 

 

 

 

 

 

 

 

 

 

 

 

Low pressure

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ŒOil temperature

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Probable cause

Insufficient amount of oil in the system

 

 

 

 

 

 

(1) The length of system tubing exceeds the allowable tubing length.

 

 

 

(2) The difference in height between system units exceeds the allowable value.

 

 

 

(3)

A large amount of oil was drained when a compressor was replaced.

 

 

 

(4)

Oil has accumulated in a stopped outdoor unit and has not returned, as a result of refrigerant

 

 

 

 

circuit clogging or valve leakage at the stopped outdoor unit.

 

 

 

 

 

 

 

(5)

A valve (ORVR, BALV, BPB) in the oil circuit has malfunctioned, or there is clogging of the

 

 

 

 

circuit (capillaries) which returns oil from the oil separator to the compressor.

5

 

 

(6)

If an excessive amount or liquid returns to the compressor, oil foaming may increase oil

 

 

 

discharge. The same occurs when the refrigerant proportion in the compressor is high at start,

 

 

 

 

due to an open circuit in the crank case heater.

 

 

 

(7)

Oil sensor disconnected or open circuit

 

 

 

 

 

Check

(1) Check the tubing length and height differences.

 

 

 

(2)

Check the operation of system circuit valves.

 

 

 

 

 

 

(3)

Check that there is not an excessive amount of liquid return. (Check that there is no

 

 

 

 

mechanical valve leakage.)

 

 

 

 

 

 

(4)

Check the crank case heater (wintertime).

 

 

 

 

 

 

(5)

Check that the oil sensor is not disconnected, and that the circuit is not open.

 

 

Correction

(1) If insufficient oil is a possibility, then charge with additional oil.

 

 

 

(2)

If it is clear that a valve failure has occurred, replace the valve.

 

 

Example

 

 

 

 

 

 

 

 

 

 

 

 

Notes

 

 

 

 

 

 

 

 

 

 

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Sanyo CHDX09663, CHDXR09663, CHDX07263, CHDXR07263* service manual H07 Alarm Alarm code