FULTON FT-0080C, Инструкция по установке, эксплуатации, обслуживанию и каталог запасных частей

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FT-C Vertical Electric Thermal Fluid Heater Manual 12 2013 ISSUE 1
Page 65
4
4.5
TROUBLESHOOTING
4.5.1
TROUBLESHOOTING : FLOW CIRCUIT/CIRCULATING PUMP(S)
a) The flow circuit is the electrical circuit that enables the circulating pump(s). Your thermal fluid
pump(s) will remain on until the flow circuit opens to disable the pump starter or the Off /
Pump / Heat switch is turned to the "Off" position.
b) Items in the flow circuit may include paddle type flow switches, a high inlet pressure switch, a
low inlet pressure switch, a high outlet pressure switch and a differential pressure switch.
c) Low Inlet Pressure Switch
1. All C-Model heaters have a Low Inlet Pressure Switch. This is a normally open switch that
closes with proper heater inlet pressure.
2. The purpose of the Low Inlet Pressure Switch is primarily to protect the heater from a
low flow condition. The Low Inlet Pressure Switch should be set at 0.35 barg below the
normal heater inlet pressure as read at operating temperature, assuming that none of the
conditions mentioned below are true. A tripped Low Inlet Pressure Switch is an indication
of one of the following:
d) Plugged circulation pump strainer basket
1. A plugged strainer will result in a decrease of flow through the heater. High vacuums
developed from plugged strainers can also stress the seals of the pump causing the
pump to fail.
2. A "Pump Suction" gauge is provided on Fulton thermal fluid packages to help determine
when a strainer needs cleaning. Generally this point is between 0 and -0.17 barg.
3. If the strainer is plugged, isolate the strainer and drain that section of piping being mindful
of the temperature of the thermal fluid.
4. Remove the strainer and clean with compressed air, high-pressure water or a cleaning
solution. Replace and observe new pump suction pressure.
e) Failed circulation pump coupling
1. A failed coupling will result in a decreased or no flow condition through the heater. The
coupling can be checked by removing the coupling guard between the pump and pump
motor.
2. The coupling should not be torn or misshapen. If the coupling needs to be replaced, it
is recommended to re-align the circulating pump first at ambient temperature and again
when it's at operating temperature. Alignment should be within pump manufacturers'
specifications.
f) Cavitation of the circulating pump
1. Cavitation occurs when a pump experiences a loss of head or if any low heater flashes to
gas at the impeller. During this time, the pump impeller spins without actually circulating
any thermal fluid.
2. If Fulton Ltd provided the heater skid, loss of head to the pump is extremely unlikely with
proper fluid level in the combination tank.
3. The most common low heater in a thermal piping system is water, which needs to be
boiled out at start-up or anytime new piping or fluid is added to the thermal oil system.