OM 200MICRO
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temperature and line 2, field 2 indicates the leaving condenser water temperature. Line 3, field 1
indicates the evaporator delta temperature. This is the difference between the entering and leaving
water temperature and indicates the 'load' on the chiller and the performance of the chiller. Line 3, field
2 indicates the condenser delta temperature. The design delta temperature of the evaporator and
condenser should be recorded. Any large changes in the delta temperatures is an indication of
potential problems that could be associated with fouled condenser or evaporator tubes.
Press the "NEXT ITEM" key and screen 2 will display additional information. Line 1, field 1 will
indicate the entering heat recovery temperature.
(This is an optional operating parameter and it will
display a value only if the optional heat recovery sensors are installed.)
Line 1, field 2 will indicate
the flow rate through the evaporator in gallons per minute
(gpm
). (This is an option and the optional
flow meter must be installed in the piping system.) Line 2, field 1 indicates the leaving heat recovery
water temperature
(optional)
. Line 2, field 2 indicates the condenser water flow in gallons per minute
(optional)
. Line 3, filed 1 indicates the delta temperature of the heat recovery system
(optional)
. The
delta temperature of the heat recovery system multiplied by the water flow rate and a special factor
would provide the amount of heat recovered in Btu's. This information could be compared to design
conditions to determine system operation. Pressing the switch key will toggle between this menu and
Menu 12
(Leaving Evap Set Points)
. This allows the operator to compare actual operating conditions
versus set points.
Menu 2, Water Temperatures
Item
Screen
Line
Display
Field
Range
Extended Name
Ent Evap=xx.x°F
1
Entering Evap Water Temp
1
Ent Cond=xx.x°F
2
Entering Cond Water Temp
Lvg Evap=xx.x°F
1
Leaving Evap Water Temp
2
Lvg Cond=xx.x°F
2
Leaving Cond Water Temp
Delta T=xx.x°F
1
Evap Water Delta Temp
1
3
Delta T=xx.x°F
2
Cond Water Delta Temp
Ent Ht Rcvy=xx.x°F
1
Heat Recvy Ent Water Temp
1
Evap Flow=xxxxgpm
2
Averaged Evap Water Flow
Lvg Ht Rcvy=xx.x°F
1
Heat Recv Lvg Water Temp
2
Cond Flow=xxxxgpm
2
Averaged Cond Water Flow
2
3
Delta T=xx.x°F
1
Heat Rcvy Delta Temp
Press the "NEXT MENU" key and Menu 3
(Refrig Temps/Press)
will be displayed. This menu has
three screens. The refrigerant temperatures and pressures allows the operator to determine if the
chiller is performing properly. These values should be recorded in a chiller log on a daily basis. The
values will change as the load, condenser temperature and evaporator temperature vary. The operator
should be able to correlate displayed information to varying load conditions.
Screen 1, line 1, field 1 indicates the saturated evaporator refrigerant pressure and temperature. The
evaporator pressure is measured using a pressure transducer and the associated temperature is
calculated using refrigerant tables stored in the computer memory. Line 2, field 1 indicates the
saturated condenser refrigerant pressure and temperature. The condenser pressure is measured using
a pressure transducer and the associated temperature is calculated. Line 3, field 1 indicates the
suction line temperature. This is measured with a thermister in the inlet suction pipe before the inlet
guide vanes at the compressor. Line 3, field 2 indicates the liquid line temperature and is measured
with a thermister in the liquid line leaving the condenser.
Press the "NEXT ITEM" key and screen two will display additional information. Screen 2, line 1, field
1 indicates the suction superheat. This value is determined by subtracting the saturated evaporator
temperature from the suction line temperature. Line 1, field 2 indicates the amount of subcooling of
the liquid refrigerant. This temperature is calculated by subtracting the liquid line temperature from
the condenser temperature. Line 2, field 1 indicates the refrigerant temperature after it leaves the
compressor and before entering the condenser. Line 2, field 2 indicates the condenser approach
temperature. This temperature is calculated by subtracting the leaving condenser water temperature
from the saturated condenser refrigerant temperature. Line 3, field 1 indicates the discharge refrigerant
superheat. This temperature is calculated by subtracting the refrigerant saturated condenser
temperature from the refrigerant discharge temperature. Line 3, field 2 indicates the evaporator
