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FORM 150.24-NM27
YORK INTERNATIONAL
67
FIG. 22
LEAVING WATER CONTROL LOADING/UNLOADING
Within the lower half of the CONTROL RANGE, the
micro-processor may call for further unloading if the Rate
Sensitivity is exceeded. If temperature drop exceeds 1X
the Rate Sensitivity, the micro will unload the chiller to
prevent overshoot.
Normal unloading will occur if leaving water temperature
should fall into the temperature range BELOW THE
CONTROL RANGE which is below the programmed LOW
LIMIT WATER TEMPERATURE. The microprocessor will
unload the chiller in 20 sec. intervals until water tem-
perature rises back into the CONTROL RANGE.
If leaving water temperature rises to the upper half of
CONTROL RANGE or above, the microprocessor will load
the chiller as needed in 150 sec. intervals until tempera-
tures fall into the lower half of the CONTROL RANGE. If
the rate of drop in water temperature exceeds 2X the
programmed Rate Sensitivity, no further loading or un-
loading will result since the micro sees the temperature
dropping at an excessive rate anticipating temperature
will soon fall into the CONTROL RANGE.
The micro is capable of providing 5, 7, or 10 steps of
loading/unloading although 10 steps is not available with
the compressors utilized. The chiller MUST be pro-
grammed for the number of steps were ordered. Other-
wise, improper operation and water temperature control
problems will result.
NOTE: The micro controls loading and unloading re-
sponses on a 10 step scale regardless of the
number of stages present. Therefore, loading
and unloading responses on 5 and 7 step chill-
ers may appear delayed (time between steps
increased) when missing steps are activated or
de-activated by the micro, 5 STEP CONTROL
IS STANDARD.
Fig. 22 shows the loading and unloading sequences for
5, 7 and 10 steps of control.
5 STEP (STANDARD)
TEMPERATURE
RISE
LOAD
UNLOAD
5.
LEAD COMP + 1 STEP,
LAG COMP + 1 STEP
_ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
4.
LEAD COMP + 1 STEP,
LAG COMP UNLOADED
_ _ _
LEAD COMP + 1 STEP,
LAG COMP UNLOADED
3.
LEAD COMP UNLOADED,
LAG COMP UNLOADED
_ _ _
LEAD COMP UNLOADED,
LAG COMP UNLOADED
2.
LEAD COMP + 1 STEP,
LAG COMP OFF
_ _ _
LEAD COMP + 1 STEP,
LAG COMP OFF
1.
LEAD COMP UNLOADED,
LAG COMP OFF
_ _ _
LEAD COMP UNLOADED,
LAG COMP OFF
LEAD COMP OFF,
LAG COMP OFF
_ _ _
LEAD COMP OFF,
LAG COMP OFF
TEMPERATURE
FALL
7 STEP (STANDARD)
TEMPERATURE
RISE
LOAD
UNLOAD
7.
LEAD COMP + 2 STEPS,
LAG COMP + 2 STEPS
_ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
6.
LEAD COMP + 2 STEPS,
LAG COMP + 1 STEP
_ _ _
LEAD COMP + 2 STEPS,
LAG COMP + 1 STEP
5.
LEAD COMP + 1 STEP,
LAG COMP + 1 STEP
_ _ _
LEAD COMP + 1 STEP,
LAG COMP + 1 STEP
4.
LEAD COMP + 1 STEP,
LAG COMP UNLOADED
_ _ _
LEAD COMP + 1 STEP,
LAG COMP UNLOADED
3.
LEAD COMP + 2 STEPS,
LAG COMP OFF
_ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
2.
LEAD COMP + 1 STEP,
LAG COMP OFF
_ _ _
LEAD COMP + 1 STEP,
LAG COMP OFF
1.
LEAD COMP UNLOADED,
LAG COMP OFF
_ _ _
LEAD COMP UNLOADED,
LAG COMP OFF
LEAD COMP OFF,
LAG COMP OFF
_ _ _
LEAD COMP OFF,
LAG COMP OFF
TEMPERATURE
FALL
10 STEP
TEMPERATURE
RISE
LOAD
UNLOAD
10.
LEAD COMP + 3 STEPS,
LAG COMP + 3 STEPS
_ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
9.
LEAD COMP + 3 STEPS,
LAG COMP + 2 STEPS
_ _ _
LEAD COMP + 3 STEPS,
LAG COMP + 2 STEPS
8.
LEAD COMP + 2 STEPS,
LAG COMP + 12 STEPS
_ _ _
LEAD COMP + 2 STEPS,
LAG COMP + 2 STEPS
7.
LEAD COMP + 2 STEPS,
LAG COMP + 1 STEP
_ _ _
LEAD COMP + 2 STEPS,
LAG COMP + 1 STEP
6.
LEAD COMP + 1 STEP,
LAG COMP + 1 STEP
_ _ _
LEAD COMP + 1 STEP,
LAG COMP + 1 STEP
5.
LEAD COMP + 1 STEP,
LAG COMP UNLOADED
_ _ _
LEAD COMP + 1 STEP,
LAG COMP UNLOADED
4.
LEAD COMP + 3 STEPS,
LAG COMP OFF
_ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
3.
LEAD COMP + 2 STEPS,
LAG COMP OFF
_ _ _
LEAD COMP + 2 STEPS,
LAG COMP OFF
2.
LEAD COMP + 1 STEP,
LAG COMP OFF
_ _ _
LEAD COMP + 1 STEP,
LAG COMP OFF
1.
LEAD COMP UNLOADED
LAG COMP OFF
_ _ _
LEAD COMP UNLOADED,
LAG COMP OFF
LEAD COMP OFF,
LAG COMP OFF
_ _ _
LEAD COMP OFF,
LAG COMP OFF
TEMPERATURE
FALL
* This step is skipped on a temperature drop.
Summary of Contents for YCWJ45EE0
Page 29: ...FORM 150 24 NM27 YORK INTERNATIONAL 29 CONTROL CIRCUIT With I O Expansion Board LD02106...
Page 30: ...30 YORK INTERNATIONAL FIG 9 SYSTEM WIRING...
Page 31: ...FORM 150 24 NM27 YORK INTERNATIONAL 31 LD02678...
Page 35: ...FORM 150 24 NM27 YORK INTERNATIONAL 35 LD02679...
Page 36: ...36 YORK INTERNATIONAL MICROPANEL CONNECTION DIAGRAM With I O Expansion Board LD02107...
Page 37: ...FORM 150 24 NM27 YORK INTERNATIONAL 37 LD02108...