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 54
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3.9.7
GAS PRESSURE SWITCH
3.9.6
HIGH AND LOW FLUID PRESSURE SWITCHES
The heater is equipped with a low inlet, high inlet and high outlet pressure switch. See Figure 6.
The switches are located on the side of heater panel with tubing connections to the respective
heater inlet and outlet manifolds. The switches are used to ensure proper flow through the heater
(no restrictions in the piping system). The switches must be set at startup and the setpoints are
based on the system design/performance.
The only pressure required in the thermal fluid system is the pressure required to maintain the
proper flow. Pressure changes are monitored with these switches, which will shut the unit down in
case of a change in the fluid flow.
To Test The Switches
1. With three position switch set to “Pump”, remove the cover from the pressure switch and
manally trip the switch. Pump should shut down.
2. Repeat for each switch; replace covers. Note, if the burner was on, it would also stop.
3. To set the inlet low fluid pressure cutout switch, raise the setpoint with the fluid at operating
temperature and pump running, until the pump shuts down. Note the setpoint and lower by 0.7
barg, then restart pump. The setpoint at cutout should correspond to the reading on the inlet
pressure gauge.
4. With the unit cold and pump running, lower the high fluid pressure cutout switch until the pump
shuts down. Note the setpoint and raise by 10 PSI, then re-start pump. The setpoint at cutout
should correspond to the inlet gauge reading.
5. With the unit running at operating temperature, lower the high outlet pressure switch until the
pump shuts down. Note the setpoint and raise by 0.7 barg, then restart the pump. The setpoint
of this switch should correspond to the outlet pressure gauge reading.
Note: Switch settings shall never exceed the safety valve set pressure.
Note:
Gas Fired Units Only
The high and low gas pressure switches are located on the gas train See Figure 24. The switches
are used to ensure that the incoming gas pressure and gas pressure to the burner are within the
appropriate range.
1. While firing, shut the main gas ball valve closest to the burner.
2. Unit will lock out on high gas pressure.
3. Attempt restart by resetting flame programmer.
4. Unit will start purge and lock out.
5. Open the gas valve closest to the burner and reset flame programmer.
6. Reset high side of switch, unit will start purge and fire.
7. To test the low gas pressure switch, close the incoming manual valve.
8. Allow the control to sequence.
9. When the gas valves energize, the heater should lock out.
10. Reset the low side of the switch/reset flame programmer and open the upstream manual valve.
11. The unit will start purge and fire.