Advantage Sentra SK Series, Инструкция по эксплуатации

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Temperature Control Units : Sentra with VE Series Instrument
Page: 34
Advantage Engineering, Inc.
525 East Stop 18 Road Greenwood, Indiana 46142
317-887-0729 Fax: 317-881-1277
Service Department Fax: 317-885-8683
www.AdvantageEngineering.com
to instructions outlined in this manual and return the assembly to the
factory. The instrument is not a field serviceable component.
4.5 UNIT UNDERHEATS
A. This is evidence by operations with To Process temperatures consistently below the
selected setpoint temperature.
1. Process water leakage. When the instrument engages the heater to elevate
process temperature, the input of heat into the process can be offset by a
defective PVT
TM
valve. If the PVT
TM
valve is defective, it may pass a larger than
required stream to drain, thus providing unwanted cooling. A defective PVT
TM
valve should be repaired immediately.
2. Heater element failure. A failed heater element will not input adequate heat
into the process to elevate the process water temperature. The operator must
check the amps at the heater contactor with the contactor energized. Zero amps
at the contactor indicate a failed heater or burnt wire connections. The operator
should remove the failed heater and replace with a new heater according to the
procedure outlined in section 5.2.
3. Unit capacity too low. This occurs when the process requires more heat than
the unit is capable of producing. The only option in such cases is to install a unit
with an adequate heater KW rating for the load.
4. Instrument defective. The instrument is designed and manufactured exclusively
by Advantage. The instrument is life-tested and found to be field reliable.
However, in the case where the instrument is determined to be defective, the
operator must remove the assembly according to instructions outlined in this
manual and return the assembly to the factory. The instrument is not a field
serviceable component.
4.6 PRESSURE RELIEF VALVE LEAKS
A. The unit has a 150 psi pressure relief valve mounted in the cooling cylinder. If the valve is
found to be leaking, the operator should check the following:
B. Water supply pressure exceeds 75 psi. The unit is designed to operate with water
supply NOT exceeding 75 psi. See section 2.3 paragraph B for specific water supply
pressure requirements at corresponding setpoint temperatures. If the plant water supply
pressure exceeds 75 psi, the pressure relief valve may leak. Static water supply pressure
can be determined at the unit’s location by reading the unit’s 0-160 PSI pressure gauges
when the unit’s motor pump is off. If the water supply pressure at the unit’s location
exceeds 75 PSI, a pressure reducing valve must be installed in the water supply line. The
factory recommended ‘regulated pressure out’ is 55 PSI. Refer to section 7.4 for regulator
installation drawing.
C. Back flow prevention device in water supply line. If a back flow prevention device
(check valve, pressure regulator, closed valve) is installed in the water supply line,
increased pressures from thermal expansion are unable to move into the water supply
line. This will increase the unit’s internal pressure causing the pressure relief valve to
leak. Refer to section 7.4 for regulator installation drawing.