Johnson Controls YORK YK MaxE, Operation Manual

Page: 89 / 184

FORM 160.54-O1
89
JOHNSON CONTROLS
2
Delta P/P
Displays chiller head pressure calculated as (condenser
pressure - evaporator pressure/evaporator pressure). This
value is calculated by the Microboard.
Temperature Differential (LCHLT – Setpoint)
Displays the difference between the leaving chilled
liquid temperature and the leaving chilled liquid tem-
perature setpoint.
Command Frequency
This is the speed command being sent to the Drive
Logic Board in either AUTO or MANUAL speed con-
trol mode.
Speed Decrease Inhibit – Surge Map Point (LED)
Illuminates when the Microboard ACC function is
unable to reduce speed due to a mapped surge point.
Otherwise, it is extinguished.
Mapping Inhibited (LED)
Illuminates when the Microboard ACC function is not
permitted to map points or reduce speed due to unstable
Leaving Chilled Liquid Temperature, manual speed con-
trol, current limit in effect (chiller FLA only) or during
Soft Shutdown (software version C.OPT.01.21.307 and
later). Otherwise, it is extinguished.
ACC Surge Detected (LED)
Illuminates momentarily when a surge is detected by
the ACC function in the Microboard, while the drive is
running at less than maximum frequency.
Surge Avoidance Surge Detected (LED)
Illuminates momentarily when a surge is detected by
the Surge Protection feature. This feature only detects
surges that occur while the drive is running at maximum
frequency.
ACC Surge Count
Increments when a surge is detected while the drive is
running at less than maximum frequency.
Surge Map Point Count
Displays the total number of data points contained in
the surge map.
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VSD Start Frequency
(Software version C.OPT.01.21.307 and later)
Sets the starting frequency from which the ramp-up will
begin. Programmable over the following range: 60Hz
units – 30Hz to 60Hz (default 45Hz), 60Hz units with
Quick Restart-30Hz to 45Hz (default 45Hz), 50Hz units
– 25Hz to 50Hz (default 37.5 Hz), 50Hz units with Quick
Restart – 25Hz to 37.5Hz (default 37.5Hz).
ACC Mapping Enable
(Software version C.OPT.01.21.307 and later)
Sets the Delta T (Leaving Chilled Liquid Temperature
- Setpoint) needed to be met to enable surge mapping
and speed reduction initially on startup. Programmable
over the range of 0.5ºF to 4.0ºF (default 1.0ºF).
Surge Margin Adjust
This value determines how close the frequency reduc-
tion will be allowed to get to the surge line. Program-
mable over the range of 0.0 (default) to 25.0Hz. Service
Technicians should refer to YORK VSD Service Manual
160.00-M4 prior to adjusting this setpoint.
Surge Sensitivity
Allows the Service Technician to adjust the sensitivity
of the ACC surge detection in the Microboard (surges
that occur while the drive is running at less than maxi-
mum frequency). Programmable over the range of 1.5
to 2.5 with default of 2.0. Smaller values increase the
sensitivity.
Auto Map Print (Enable/Disable)
When enabled, the ACC surge map values are printed to
a connected printer each time a surge point is mapped,
as shown in Section 3 of this book.
Manual Surge Point
Allows the Service Technician to manually log the pres-
ent running operating conditions into the surge map as
a valid surge point. When this key is pressed, a dialog
box appears requesting a special password to proceed.
Service Technicians refer to procedure and password
in YORK OptiView Service Manual 160.54-M1 sec-
tion 23.