Troubleshooting And Countermeasure; No Drop Of Chilled Water Temperature In Cooling Operation; No Rise Of Hot Water Temperature In Heating Operation - Hyundai HDFN-80-1400 Operation Instructions Manual

10.

Troubleshooting and Countermeasure

It was already stated in the previous chapter that it is important to know whether or not the chiller-
heater was operating normally in daily inspection and maintenance. When trouble occurs, the
countermeasures itemized in the chapter should be taken quickly in order to restore the normal
operation of the chiller-heater. The causes of troubles and their countermeasures are shown by
item as follows :

10.1 No Drop of Chilled Water Temperature in Cooling Operation

Cause
Degree of vacuum is low
Fuel flow rate is short
Cooling water inlet temperature is high
Cooling water flow rate is short
Tubes for cooling water are dirty
Refrigerant is dirty
Crystallization
Chilled water flow rate is too much

10.2 No Rise of Hot Water Temperature in Heating Operation

Cause
Fuel flow rate is short
Hot water flow rate is too much
Degree of vacuum is low
Steps to be Taken
 Purge air (purge pump operation)
 When vacuum is still low purging, do leak test and then
proceed the following work :
 Fasten the flange part
 Check the purge solenoid valve
 Check if the service valve is closed
 Check the purge pump
 Check and adjust fuel supply pressure
 Check and clean the strainer
 Adjust the opening of fuel control valve and air damper
 Check the cooling tower
 Check cooling water temperature control system
 Check the cooling
 Check cooling water temperature control system
 Check the cooling water pump and cooling water
system
 Clean the cooling water tubes
Note : For chilled water tubes same countermeasure is
taken.
 Re-generate refrigerant (Refer to 5.7 Service
Operation)
 Refer to 7.2 for how to de-crystallize. Check the
following to eliminate cause of crystallization
 Whether cooling water inlet temperature is too low
 Whether degree of vacuum is low
 Whether time for dilute operation after stopping the
operation of the chiller-heater is too short
 Set the flow rate to the rating
Steps to be Taken
 Check and adjust fuel supply pressure
 Check and clean the strainer
 Check opening of the fuel control valve and air damper
 Set the hot water flow rate to the rating
 Purge air (purge pump operation)
 When vacuum is still low after purging, do leak test and
then proceed the following work :
 Fasten the flange part
 Check if the service valve is closed
 Check the purge pump
 Check the purge solenoid valve
57