Armstrong World Industries EHU-703, EHU-701 manual Month to 1 Year, Steam Generator Maintenance

MAINTENANCE

RECOMMENDED MAINTENANCE SCHEDULE

1 TO 2 DAYS AFTER START UP

1)Check unit operation.

2)Look in drain pan for leaks.

3)Check steam piping for leaks.

4)Observe duct low points for signs of poor humidity distribution.

5)Be sure unit is draining freely by pushing the manual drain button (the manual tank off button should not be depressed).

1 MONTH TO 1 YEAR	1)	Repeat the 5 steps outlined above.
	2)	Clean, repair, or replace steam generator.

STEAM GENERATOR MAINTENANCE

General:

The steam generator is basically the only part of the EHU that requires regular maintenance. This maintenance may include cleaning or replacing the tank itself or the electrodes. We recommend sub- stituting a spare generator in order to minimize downtime and labor requirements. The replaced gener- ator may then be serviced when it is convenient.

Tank Cleaning:

As the water in the steam generator boils away, the minerals in that water come out of suspension and are deposited on the walls of the tank and on the electrodes. This process leaves the tank walls coat- ed with a white or light brown colored mineral buildup. This buildup may be anywhere from soft and chalky to rock hard. The automatic drain cycle will minimize mineral buildup but, eventually, the tank will need cleaning.

Tank cleaning is indicated when:

a)The unit has been in service for a period of time, a solids buildup is visible through the tank walls, and the "normal" water level in the tank is rising, or;

b)The tank cleaning message (C02) is displayed.

TO CLEAN THE TANK, PLEASE REFER TO THE "TANK REMOVAL AND REPLACEMENT" AND THE "STEAM GENERATOR CHEMICAL CLEANING PROCESS" SECTIONS OF THIS MANUAL. (PAGE 30)

Tank Replacement:

Tank replacement is indicated if the tank body becomes deformed in any way, as this could cause leakage around the o-ring.

TO REPLACE THE TANK, PLEASE REFER TO THE "TANK REMOVAL AND REPLACEMENT" SECTION OF THIS MANUAL. (Page 30)

Electrode Replacement:

Electrode disintegration generally starts due to high conductivity water being present in the steam generator. Electrode disintegration sometimes occurs as a result of a combination of the following factors:

a)High voltage (especially 480 and 600 volts);

b)Hard water (in excess of 20 grains/gal.);

c)Any unit with a malfunctioning drain system;

d)Softened water.

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