Temptek VETERAN LS Series, Инструкция по эксплуатации

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Temperature Control Units : With ‘LS’ Series Instrument
Page: 72
TEMPTEK, INC.
525 East Stop 18 Road Greenwood, Indiana 46142
317-887-6352 Fax: 317-881-1277
Service Department Fax: 317-885-8683
www.Temptek.com
8.3 INTERPRETATION OF PROCESS PRESSURE GAUGES
A. READ AVAILABLE WATER
PRESSURE AT UNIT’S
LOCATION. When a temperature
control unit is attached to the
process with the water supply on
and the pump off, both gauges will
read the water supply pressure at
the unit’s location (figure 7.3A).
B. READ PRESSURE DROP
ACROSS PROCESS (∆ P). With
the pump on, the “to process”
pressure gauge will rise to read the
sum of the water supply pressure
and pump generated pressure. The “from process” pressure
gauge reads the effect of water supply pressure and pump suction
pressure. The difference between the to and from process gauges
is the pump generated circulating pressure... which is also equal to
the pressure drop across the process.
C. PUMP ROTATION INDICATION. If the pump is running, and
both gauges are “close” to same value, it is likely that the pump is
rotating backward, or the pump is generating such a high flow that
an overload condition will result.
D. PUMP MOTOR OVERLOAD CONDITION. If the ∆ P is low with the
pump rotating correctly, then the flow rate is high, which probably
will result in a motor overload. Refer to the representative pump
curve below.
E. WATER HAMMER (COMPETITIVE SOLENOID VALVE UNITS).
On competitive mold temperature controllers, when ∆ P gauges are
supplied, the water hammer effect of on/off solenoid valves can be
seen. When the solenoid valve is open, both to and from process
pressure gauges will fall as the system depressurizes. When the
valve closes, there will be a momentary spike that will be seen
on both pressure gauges, then they will settle back to normal ∆ P
values. This spike is called “water hammer”.
Pressure gauges
Figure 7.3A