Roberts Gorden CTCU 32, CTCU 27 Gas Valve for Heater Models, Check Gas Rate, Combustion Testing

Models: CTCU 32 CTCU 7 CTCU 22 CTCU 11 CTCU 15 CTCU 27

1 50
Download 50 pages 34.89 Kb
Page 29
Image 29
Figure 12: Gas Valve for Heater (Models 7 - 32)

SECTION 11: COMMISSIONING

Figure 12: Gas Valve for Heater (Models 7 - 32)

11.4.2Commissioning the Gas Valves (all gases) 11.4.2.1 Check Burner Gas Pressure

1. Loosen the screw cover of the outlet (burner) pressure test point and connect a manometer.

2.With the burner firing, measure the pressure on the manometer. To adjust the burner pressure, remove the regulator cover from the valve and turn the regulator adjustment screw to set the required burner pressure as stated in the Tech- nical Data Tables for the correct gas and model on Page 9, Section 5.3.

NOTE: If the correct burner pressure cannot be reached, then check the inlet pressure to the valve, with the burner firing. See Technical Data Tables on Page 9, Section 5.3 for inlet pressure requirement.

must be tested to prove correct heater operation. Incorrect results will indicate faults with the installation or appliance.

Combustion testing must be carried out with all

covers in place. The flue gas is sampled in the flue, within 1 meter of the heater. The values of CO2 should be between 5.7% to 8.0% for natural gas and 6.8% to 9.2% for LPG dependant upon model.

The CO will be up to 80 ppm (0.008%) dry, air free dependant upon model. Temperature rise of the flue gases above ambient should be approximately 130° C to 160° C. Seal test hole in flue after testing.

Pressure Switch:The pressure switch is factory pre- set for each model and is not adjustable.

Do not continue to adjust the regulator if the pressure is not changing.

If the inlet pressure is too low to allow correct burner pressure setting, then the gas inlet pressure must be corrected before completing the commission.

Check Gas Rate

1.After burner pressure adjustment, allow the heater to operate for at least 15 minutes and then re-check settings.

2.Remove the manometer and refit all covers to the valve and tighten the screw of the outlet pressure tap.

3.Check gas flow rate at gas meter.

11.5 Combustion Testing

The only adjustment to alter combustion performance is burner pressure. Combustion quality

11.6 Turning Off the Heater

Set the external controls to the off position and the main burner will stop.

The fans will run until they are stopped automatically by the fan thermostat.

Do not use electrical isolator for control of heater. Electrical isolator will switch off the fan. Heat exchanger could be damaged. Warranty will not cover damage to the heat exchanger if operated improperly.

11.7 External Controls

External controls may include time switch, room thermostat and frost thermostat. Operate each control to ensure that they function correctly. Set the time switch (if fitted) and room thermostat to the users’ requirements.

23 of 42

Page 29
Image 29
Roberts Gorden CTCU 32, CTCU 27 Gas Valve for Heater Models, Check Gas Rate, Combustion Testing, Turning Off the Heater