Maintenance schedule – American Dryer Corp. AD-840 User Manual

Page 21

American Dispensing Company

88 Currant Road / Fall River, MA 02720-4781

SECTION VI

MAINTENANCE SCHEDULE

Maintenance frequency of the vending machine depends on the use of the machine and the feed water quality.
The best way to determine when filters and other components should be changed is to keep a log of tests done
and the date and gallon reading at which they are done. For additional information on maintenance of the
components, please refer to the appropriate sections in the manual.

WARNING: REPLACE COMPONENTS ONLY WITH ORIGINAL FACTORY REPLACE-

MENTS. COMPONENTS OF DIFFERENT BRANDS MAY NOT WORK
PROPERLY WITH OTHER PARTS IN THE MACHINE AND MAY CAUSE
DAMAGE TO THEM AND TO THE HEALTH OF YOUR CUSTOMERS.

1. Strainer

Test:

Monitor pressure drop at sediment filter. Clean or replace after 2 psi drop.

Replace/Clean

Establish frequency from test, clean at least once a month.

Frequency:

Failure Mode:

Clogged, and cause a pressure drop large enough to shut off the R.O. pump, reducing
yield of the R.O. Membrane to a trickle.

2. Sediment Filter

Test:

Visual, change when dirt penetrates more than 2/3 of the filter or when pressure differ-
ential is 10 psi or more, whichever is first. CHECK WEEKLY.

Replace/Clean

Establish frequency from test, clean at least once a month.

Frequency:

Failure Mode:

Clogged, and cause a pressure drop large enough to shut off the R.O. pump, reducing
yield of the R.O. Membrane to a trickle.

3. Carbon Filter

Test:

Use free chlorine test kit. Free chlorine level should be less than .1 ppm. Test at 5
gal., 10,000 gal., 18,000 gal. and after every replacement.

Replace/Clean

Replace at any trace of free chlorine (.1 ppm or higher) but no less frequently than

Frequency:

once every 20,000 gallons or every three months, whichever comes first.

Failure Mode:

Any chlorine not contained by the carbon filter will leak to the R.O. membrane and
cause irreparable damage to it. Always replace the carbon filter before it’s time. A
damaged R.O. membrane costs over ten times more to replace than a carbon filter.