York SSS 14L-B, Руководство по эксплуатации

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JOHNSON CONTROLS
14
FORM 160.00-O2
ISSUE DATE: 04/30/2019
SECTION 1 – THEORY OF OPERATION
ELECTRICAL CONDITIONS
Proper starter operation requires that all phases of the
AC power line voltage are present, and in the correct
rotation. A “Power Fault” circuit provides protection
from rapid power line current interruptions and tran-
sient switching. The AC power line voltage also must
be relatively free of spikes and noise. If these condi-
tions are not met, safety circuitry on the Logic/Trig-
ger Board will cause a shutdown of the LCSSS. These
shutdowns will protect the chiller from rotating in the
wrong direction, or causing transient torque conditions
on the compressor shaft. As well, the LCSSS will shut
down and protect itself and the compressor motor if
the AC power line voltage is too high or too low.
If the LCSSS is intended to be used on a generator
application, then the JP1 jumper on the Logic/Trigger
Board may need to be cut. Even if the starter will be
connected to a generator for emergency power, the JP1
jumper may need to be cut. The JP1 jumper changes
how the Logic/Trigger Board will track the frequency
of the incoming line voltage. (See Figure 6 on page
18 for location of JP1.) If the Logic/Trigger Board
is a Rev. C, then the JP1 jumper must be cut for gen-
erator operation. If the Logic/Trigger Board is a Rev.
D or later, the JP1 jumper has been removed, and the
Logic/Trigger Board will function properly regardless
of whether the starter is connected to the utility or gen-
erator power.
MOTOR PROTECTION
Compressor motor protection circuits are provided on
the Logic/Trigger Board. These circuits protect the
motor from continuous or instantaneous high current
levels. Another circuit is used to determine if the cur-
rent transformers are connected to the Logic/Trigger
Board. This ensures that the LCSSS has current feed-
back before the chiller is started. Without the current
feedback, the inrush current cannot be regulated. Also,
if the output current becomes imbalanced due to AC
power line voltage instability, or faulty SCR, a shut-
down will occur. Other circuits are employed to sense
a signal phase condition to the motor, or if one of the
SCRs is open.
The coolant temperature inside any JCI-supplied
liquid-cooled motor starter must be maintained
above the dewpoint temperature in the equipment
room to prevent condensing water vapor inside the
starter cabinet. Therefore, an additional tempera-
ture-controlled throttle valve is needed in the flow
path for the starter heat exchanger to regulate cool-
ing above the equipment room dewpoint for applica-
tions using cooling sources other than evaporative
air-exchange methods, such as wells, bodies of wa-
ter, and chilled water. The temperature control valve
should be the type to open on increasing drive cool-
ant temperature, fail-closed, and set for a tempera-
ture above dewpoint. It can be requested as factory-
supplied on a chiller order by special quotation.