background image

FORM 201.19-CL1 (309)

JOHNSON CONTROLS 

7

  1.  Place the System Switches on the Microproces-

sor Board to the ON position.

  2.  The compressor will start and a flow of refriger

-

ant will be noted in the sight glass. After several 

minutes of operation, the bubbles in the sight 

glass will disappear and there will be a solid col-

umn of liquid when the TXV stabilizes. After the 

water temperature stabilizes at desired operating 

conditions, the sight glass should be clear.

  3.  Allow the compressor to run a short time, being 

ready to stop it immediately if any unusual noise 

or adverse conditions develop. Immediately at 

start-up, the compressor will make sounds dif-

ferent from its normal high pitched sound. This 

is due to the compressor coming up to speed and 

lubrication changing from liquid refrigerant to 

oil. This should be of no concern and lasts for 

only a short time.

  4.  Check the system operating parameters. Do this 

by selecting various displays such as pressures 

and temperatures. Compare these to test gauge 

readings.

CHECkIng SUBCOOLIng AnD SUPERHEAt 

The subcooling should always be checked when charg-

ing the system with refrigerant and/or before setting 

the superheat.

When the refrigerant charge is correct, there will be no 

bubbles in the liquid sight glass with the system operat-

ing under full load conditions, and there will be 12 - 15°F 

(6 - 8°C) subcooled liquid leaving the condenser.

An  overcharged  system  should  be  guarded  against. 

Evidences of overcharge are as follows:
 

a.  If a system is overcharged, the discharge pressure 

will be higher than normal. (Normal discharge/

condensing pressure can be found in the refriger-

ant temperature/pressure chart; use entering air 

tempe30°F (17°C) for normal condens-

ing temperature.

 

b.  The temperature of the liquid refrigerant out of 

the condenser should be not be more than 15°F 

(8°C) less than the condensing temperature (The 

temperature corresponding to the condensing 

pressure from the refrigerant temperature/pres-

sure chart).

  8.  Set the Time and Date.

  9.  Program  the  Daily  Schedule  start  and  stop 

times.

  10. Check the Factory Service Mode programming 

values, assure they are correct, and record the 

values below:

Refrigerant Type  =     ____________________________

R407C Chiller Type = ____________________________

Unit Type =   ___________________________________                                  

Heat Recovery =  _______________________________

Sys #1 100% FLA =  _________________________Amps

Sys #2 100% FLA =  _________________________Amps

Sys #1 Motor Protector Input  =  ________________ Volts

Sys #2 Motor Protector Input  =  ________________ Volts

Typically, these values should not be 

changed.      Incorrect  programming 

may  cause  catastrophic  chiller  fail-

ure.  

  11. Check the Motor Protector Dip Switch program-

ming.  The switches should correctly set at the 

factory.  The switches may be checked visibly 

and the total ON switches added using binary 

addition to determine the setting or by reading 

the display on the motor protector.  See Section 

8  for  programming  information.    Record  the 

values below:

Sys #1 Wires thru each hole of the C.T. =  ____________

Sys #1 MP Setting =                    ____________

Sys #2 Wires thru each hole of the C.T. =  ____________

Sys #2 MP Setting  =                    ____________

InItIAL StARt-UP

After the control panel has been programmed and the 

compressor heater has been on for 24 hours prior to 

start-up, the chiller may be placed into operation.

Summary of Contents for YORK YCAS0098-0208

Page 1: ...rating charge Reference the Technical Data Section in the IOM Valves Open each compressor suction economizer and dis charge valve fully counter clockwise then close one turn of the stem to ensure operating pressure is fed to the pressure transducers Open the liquid line service valve fully and ensure the oil return line ball valve is open in each system Compressor Oil To add oil to a circuit conne...

Page 2: ... above 96 F 36 C the compressor heaters must be on for at least 8 hours before start up to ensure all refrigerant liquid is driven out of the compressor If the ambient temperature is below 86 F 30 C then allow 24 hours Water System Verify that the chilled liquid system has been installed correctly and has been commissioned with the correct direction of water flow through the evaporator The inlet s...

Page 3: ...position Start up Remove the locking device from the unit Auto OFF switch which prevents unauthorized starting of the unit before commissioning Press the Status key then turn the unit switch to the 1 position to start the unit there may be a few seconds delay before the first compressor starts because of the anti recycle timer Be ready when each compressor starts to switch the unit OFF immedi atel...

Page 4: ...line temperature on the copper line beside the main liquid line service valve Measure liquid pressure at the liquid line service valve Sub cooling should be 12 F to 15 F 6 7 C to 8 3 C No bubbles should show in the sight glass If subcooling is out of range add or remove refrigerant as required Do not overcharge the unit The liquid flow to the main evaporator TXV is subcooled further by the economi...

Page 5: ...delivery tubing With the bottom suction end of the pump submerged in oil to avoid entrance of air operate the pump until oil drips from the flare nut joint allowing the air to be expelled and tighten the flare nut Open the oil charging valve on the oil separator and pump in oil until it reaches the proper level as described above In actual operation due to splashing an oil level may be seen in bot...

Page 6: ...lve electronic should always be selected when an EEV is installed Verify the selections by pressing the OPTIONS Key on the control panel Check them off in the chart above Damage to the chiller could result if switches are improperly pro grammed 5 Program the required operating values into the micro for cut outs safeties etc and record them in the chart below Record programmed values in the chart b...

Page 7: ...scharge condensing pressure can be found in the refriger ant temperature pressure chart use entering air temperature 30 F 17 C for normal condens ing temperature b The temperature of the liquid refrigerant out of the condenser should be not be more than 15 F 8 C less than the condensing temperature The temperature corresponding to the condensing pressure from the refrigerant temperature pres sure ...

Page 8: ...on superheat should be checked The superheat should be checked only after steady state operation of the chiller has been established the leaving water temperature has been pulled down to the required leaving water temperature and the unit is running in a fully loaded condition Correct superheat setting for a system is 10 12 F 6 7 C The superheat is calculated as the difference between the actual t...

Page 9: ...mately 15 minutes between adjustments for the system and the thermal expansion valve to respond and settle out Assure that superheat is set between 10 12 F 6 7 C 1 Record the motor gas temperature economizer pressure economizer pressure converted to temperature and economizer superheat below SYS 1 SYS 2 Economizer Press PSIG kPa Economizer Temp F C Economizer Press Converted to Temp F C Superheat ...

Reviews: