Beckett CG10 manual Flame safeguard safety lockout Simulate a

Section: Start the Burner

Check operation and safety controls

Testing by Qualified

Technician Required.

Failure to properly test and verify the correct function of operation and safety controls could lead to equipment malfunction and result in asphyxiation, explosion or fire.

yThe testing of operation and safety controls requires technical training and experience with commercial gas burning systems.

yCarefully follow the manufacturer’s instructions supplied with the controls.

yVerify the correct function of all operation and safety controls used in the installation.

yIf instructions are not available, use the following recommended procedures and record all results in a start-up log.

yRefer to Figure 7 and Figure 10 for typical test points and component locations.

1.High limit – To check the High Limit, raise the temperature or pressure of the operating control to a higher level and lower the limit to a setting less than the operating control. Run the burner until the high limit opens and shuts the burner off. Adjust the controls back to the desired settings.

2.Operating control – Run the burner until the operating control shuts it off. If necessary, make adjustments to ensure the control cycles the burner in the desired temperature or pressure range.

Operating controls should be set to minimize the number of

firing cycles that the burner runs. High cycling rates increase the possibility of light-off lock outs.

3.Low water cutoff (LWCO) – With the burner firing, open the blow down valve on the low water cutoff, if applicable. As the water level drops, the LWCO switch contacts open and shut the burner off. When the water level rises, the LWCO contacts close and restart the burner. Monitor the LWCO switch operation in relation to the water level in the sight- glass for synchronization.

4.Airflow proving switch – With the burner firing at its lowest rate, loosen the tubing connection to the airflow proving switch. A loss in air pressure at the tubing should immediately cause the diaphragm in the switch to open and recycle or lockout the safeguard control.

5.Low gas pressure switch – With the burner firing and a manometer attached to a test port near the low pressure switch, gradually close the main leak test cock to shut off the gas supply. Note the pressure at which the low gas pressure switch opens and shuts the burner off. Manually reset the switch. The low gas pressure switch should be set at half of the normal supply pressure in the line.

6.High gas pressure switch – With the burner firing and a manometer attached to the test port nearest the high pressure switch, gradually increase the gas pressure until the high pressure switch opens and shuts the burner off. Note the pressure and manually reset the switch. The high gas pressure switch should be set at one and one half times the high fire manifold pressure (see nameplate data in Figure 1 or set switch as determined by testing).

7.Leak-test valve – With the burner firing and manometer attached to the leak-test valve port, turn the burner electrical switch off and observe that the gas pressure does not increase after several minutes. This proves total closure of the main gas valve.

8.Flame safeguard safety lockout – Simulate a

flame failure by turning the main gas supply off. The control should shut the burner off on safety within the safety lockout time.

9.Flame sensor circuit (flame rod) – With the burner power switch turned off, refer to the wiring diagram supplied with the control and locate the sensor connection terminals. Place DC voltmeter probes in the flame amplifier test jacks. With the burner firing, the flame signal should be steady and at least 1.25 VDC.

10.Flame sensor circuit (UV scanner) – With the burner power switch turned off, refer to the wiring diagram supplied with the control and locate the sensor connection terminals. Place DC voltmeter probes in the flame amplifier test jacks. With the burner firing, the flame signal should be steady and at least 1.25 VDC.

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