Temptek Veteran VT LXG Series, Инструкция по эксплуатации

Страница: 81 / 96

Temperature Control Units : Veteran with LXG Series Instrument
Page: 81
TEMPTEK, INC.
525 East Stop 18 Road Greenwood, Indiana 46142
317-887-6352 Fax: 317-881-1277
Email: service@Temptek.com
8.2 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.
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