Technical information

Page: 22
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
4. EXCESSIVE FLOW... excessive
flow can overload the
process pump motor and
cause eventual failure. This is
a result of the process loop’s
ability to flow water at a
great rate than can be
provided by the process
pump. This eventually
results in tripping the
thermal motor overload
relay (overload relays open)
and the unit will shut down.
a. If an excessive flow situation is encountered and
the motor overload circuit has tripped, the operator
must manually reset the overload relay (figure 3.2E)
before operations can continue. This is done by
opening the electrical panel cover, identifying the
reset lever on the overload relay, and pushing the
reset lever “in” until the overloads are reset
(evidenced by a “clicking” sound as the overloads
reset).
5. To overcome an excessive flow condition, the operator
should set the process flow rate according to the motor
amperage:
a. Remove electrical cover panel. Note that the
electrical power is engaged at this point and
caution must be observed while the cabinet
panel is open.
b. Identify the motor
starter block. This
block consists of
the motor starter
contactor and the
overload relay.
c. Place an amp
meter on a single
power lead
emanating from
the overload relay.
d. Locate the electric pump motor. Identify
the motor name plate on the motor housing (figure
3.2F). The full load amp rating for the motor is
listed on the name plate.
e. Engage the electrical power supply and start the
motor by switching ‘on’ the CHILLER ON rocker
switch.
Figure 3.2E
Reset level on overload relay
Motor name plate
Figure 3.2F