SEELEY INTERNATIONAL AIRA DU SD Series, Инструкция по установке и эксплуатации

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DU/SD SERIES INSTALL OPERATION MAINTENANCE MANUAL | 37
UNIT MAINTENANCE
6.2.2.3 Gas Isolation Fitted and in Good Working Condition
The gas isolation valve is to be examined to make sure that it is present and in good working condition.
6.2.2.4 Gas Supply Pressure
The gas supply pressure is to be read at the unit gas valve and checked against table 4 to ensure that it falls within the
required range.
6.2.2.5 Gas Burner Pressure (High/Low)
The regulated gas pressure is to be checked at both the high and low points of the operating ranges. If the main burner
is not lighting or back burning check that the following.
1. The pilot is lit and in the correct position.
2. The correct gas injectors are installed for the type of gas (#44 for Natural Gas, #55 for LPG).
3.
Sufficient supply pressure is available.
6.2.2.6 Gas Injectors
Check that the correct injectors are installed and that they are free of debris.
6.2.2.7 Draft Diverters
Check the draft diverter for signs of damage and rust. If rust has cause loss of structural integrity the diverter is to be
replaced.
6.2.2.8 Pilot Assembly
Check that the pilot is free from damage and clear of obstructions. Ignite the heater and examine the colour and
consistency of the pilot and main burner. The pilot should be a consistent blue flame with the main burner providing a
consistent flame across all burners after ignition.
The following are the recommended steps to service the pilot assembly and main burners.
1. Uncouple pilot union at valve.
a). Uncouple thermocouple union at valve.
b). If electronic ignition – remove flame rod and ignition leads.
2. Remove screws holding pilot burner to pilot mounting bar and remove pilot burner assembly.
3.
Remove burner tubes one at a time by sliding bars sufficiently towards the front of the heater (against the spring
resistance) to disengage the rear end of the burner tube from the manifold plate; lower end of burner tube and
remove from front location plate.
4. CLEANING MAIN BURNER BARS: Lightly brush away any deposit from the burner bars and inspect for damage or
blocked ports.
5. Replace burners, making certain that they seat properly in place.
6.
Check the flame sense and igniter cabling for damage, replacing if damaged.
7. Secure the pilot assembly to the burner.
6.2.2.8.1 CLEANING PILOT BURNER:
1. THERMOCOUPLE FITTED UNITS: Wipe off any carbon deposits on end of thermocouple and ensure that pilot
burner is free from deposits.
Remove orifice spud fitting and using a small wire brush, clean pilot body, orifice and burner parts. Blow off loose
particles.
Assemble and install in original position.
On relighting, adjust pilot flame to surround thermocouple for about 10mm. Flame must be soft and blue – not
hard, noisy or yellow.
2. FLAME ROD FITTED UNITS: Wipe off any carbon deposits on flame rod, ignition electrode or ground fins and
ensure that pilot burner is free of deposits.
Remove orifice spud fitting (if fitted) and using a small wire brush, clean pilot body, orifice, electrodes and burner
parts. Blow off loose particles.
Assemble and install in original position. Adjust electrode gap between ignition electrode and pilot burner tip. This
gap MUST be 2mm to 3mm.
Flame rod gap must be adjusted to give 2 microamperes (pa) or more for stable performance. Adjust the flame rod
to produce maximum output by bending the rod to left and/or right and raising slightly if necessary. Size of pilot
flame may also require adjustment. Pilot flame must be soft and blue – not hard, noisy or yellow. Aeration shutter
(if fitted) may require adjustment.