Vilter VSM 71-701, Руководство по эксплуатации и обслуживанию

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49
Operation
FIGURE 6.
SLIDE VALVE MOTOR LOCATION
When viewing the compressor from the dis-
charge end (opposite the drive end), the up-
per motor is for capacity control. The com-
mand shaft turns (see Table 1) to decrease
the capacity to 10% and reverses to increase
the capacity to 100%. The lower motor is
for volume ratio control. The command shaft
turns (see Table 1) to reduce the volume ra-
tio to 2.0, and reverses to increase the vol-
ume ratio to 5.0.
Actuation of the electric motors can be done
manually or automatically. To actuate the
motors manually, place the desired mode
selector in the manual position and push the
manual Increase or Decrease buttons. In the
automatic mode, the microprocessor deter-
mines the direction to actuate the electric
motors. However, in the automatic mode,
there is an “On” and “Off” time for the ca-
pacity control motor. The “On” time is the
time in which the slide valve moves, and the
“Off” time is the time in which the system is
allowed to stabilize before another change
in slide valve position.
The Motor Amps Load Limit protects the
compressor from overloading by decreasing
the compressor capacity if the motor amper-
age is at the Maximum Amps setpoint, or pre-
venting an increase in capacity if the motor
amperage is above the Full Load Amps
setpoint. (See appropriate Microprocessor
Instruction Manual.)
3. Oil Separator Heater
The oil separator heater keeps the oil in the
separator from becoming too viscous and
helps to boil off refrigerant entrained in the
oil in the receiver section of the separator.
The heater is turned on only when the com-
pressor is off. The separator heater is sup-
plied with an integral temperature control.
4. Econ-O-Mizer Controls
Econ-O-Mizer ® systems are of three types:
direct expansion, flooded or flash. Flash
systems include a back pressure regulator to
control intermediate pressure.
When a direct expansion system is used, a
solenoid valve and thermostatic expansion
valve are furnished to control the degree of
subcooling. If a flooded subcooler system
or flash system is supplied, it is equipped
with a liquid solenoid valve and a float
switch to control the liquid level in the ves-
sel.
B. Safety Setpoints
A detailed explanation of all safety setpoints can
be found in the appropriate Microprocessor In-
struction Manual.
1. Oil Pressure
Low oil pressure differential stops the com-
pressor unit when there is an insufficient
difference in pressure between the oil mani-
fold and suction.
2. Discharge Pressure
High discharge pressure cutout stops the
compressor unit, when the discharge pres-
sure in the oil separator exceeds the setpoint.
View Capacity
View
Volume Ratio
Note: Optical
Actuators CAN NOT
be manually rotated.
( VSM 501-701 will
have motor locations
opposite of figure #6)