Hitachi FSG Series, Технический каталог

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17
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TEST RUN
17.5.2 FXG SYSTEM
An excess or deficiency of the refrigerant can be checked by
using data from 7-segments display check mode. This
checking procedure, as follows, is useful at test run or
maintenance.
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Before Checking:
1. Operate all the indoor units at the “TEST RUN” mode and
operate all the indoor units at the “HIGH” speed.
2. Check the following items to ensure that the refrigeration
cycle is stable.
a) The continuous operation is for more than 20 min.
b) TdSH is 20 to 40 K. [TdSH: Discharge Gas
Temperature Superheat]
c) Ps is 0.2 to 0.5 MPa. [Ps: Suction Pressure]
d) Pd is 1.4 to 2.4 MPa. [Pd: Discharge Pressure]
3. Collect the checking data by the 7-segment display check
mode. Refer to Table on page 11.
4. Perform checking as the following procedures.
Applicable Operating Conditions of Air Temperature for
Checking
[Cooling] Room Air Temperature:
20~30°C (DB)
Outdoor Air Temperature:
15 ~ 40°C (DB)
[Heating] Room Air Temperature:
20~30°C (DB)
Outdoor Air Temperature:
0~15°C (DB)
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Checking Procedures:
Cooling Operation
1. Detect oEb (Outdoor Unit Bypass Expansion Valve
Opening).
2. Compare oEb with the normal value
Normal Value: Outdoor Unit Capacity (HP) X 0.5 to
Outdoor Unit Capacity (HP) X 2
Tendency: In the case that the room air
temperature is high within the above
normal value,
the value of oEb will be big.
Judgement: oEb > Normal Value
··· This means insufficient refrigeration
oEb < Normal Value
··· This means excessive refrigerant.
Heating Operation
1. Detect oE1 and oE2 (Outdoor Unit Expansion Valve
Opening).
2. Sum up the values of oE1 and oE2
3. Compare the sum of oE1 and oE2 with the normal value.
Normal Value: 30 to 60
Tendency: When oE1 and oE2 is within the above
range and
1) In the case that the room air
temperature is high, the value of
(oE1 + oE2) will be small.
2) In the case that the outdoor air
temperature is high, the value of
(oE1 + oE2) will be big.
Judgement: (oE1 + oE2) > Normal Value
···This means insufficient refrigerant.
(oE1 + oE2) < Normal Value
··· This means excessive refrigerant.
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Cases where this method is not applicable
This checking method is not applicable under such conditions as indicated below.
In such cases, remove the causes of the conditions before checking.
Tendency of Indoor/Outdoor Expansion Valve Opening
No. Conditions
Cooling Heating
1 Short-circuited Air at Indoor Unit Tends to be Excessively Open –
2 Short-circuited Air at Outdoor Unit Tends to be Excessively Open Tends to be Excessively Closed
3
Resistance of Connecting Pipe is Big
(Due to smashed pipe or small liquid pipe)
Tends to be Excessively Open Tends to be Excessively Open
Locked (Fully Open) Tends to be Excessively Closed –
4
Indoor Unit
Expansion Valve Failure
Locked (Fully Close) Tends to be Excessively Open –
Locked (Fully Open) – Tends to be Excessively Closed
5
Outdoor Unit
Expansion Valve Failure
Locked (Fully Close) Tends to be Excessively Open Tends to be Excessively Open