Vulcan-Hart 126172, Service Manual

Page: 7 / 68

ELECTRIC COMBI OVENS - GENERAL
Page 7 of 68
WATER CONDITIONING
Furnishing the steam generator with treated water to
reduce scale formation is important. Scale formation
will reduce steam output, cause premature
component failure, and shorten equipment life. Most
water supplies contain scale producing minerals
such as Calcium and Magnesium. As steam is
generated, the minerals remain and dissolve into
the water. As the concentration of these minerals
increases past a certain point, they precipitate from
the water and coat the inside of the steam
generator, heating elements, and water level
sensors. Because of the high temperature of these
surfaces, the precipitated minerals bake onto them
and become very difficult to remove.
This may cause several problems:
1. Reduced heat transfer efficiency.
2. Premature heating element failures.
3. False readings from water level sensors.
These problems are common to any manufacturer's
steamer regardless of design, but they can all be
minimized by furnishing the steam generator with
treated water.
Other factors affecting steam generation are iron
content, amount of chloridation and dissolved
gases.
The desired water properties can best be achieved
by using a properly maintained water treatment
system.
The water level probes in the steam generator use
ions in the water to detect the water level. Do not
use fully demineralized or de-ionized water
since it is "non conductive" and the water level
can not be detected.
The use of strainers, or filters will not remove
minerals from the water.
Water supplies vary from state to state and from
locations within a state. Therefore, Vulcan
recommends that a local water treatment specialist
be consulted before the installation of any steam
generating equipment.
Steamers that operate over a long period of time
without the benefit of a water treatment system,
which have developed a heavy scale build up,
should be cleaned before using the system.
LUBRICATION
Cavity fan motor has sealed bearings and
requires no additional lubrication.
Cavity fan motor shaft seal requires lubrication
at replacement (White silicone grease 544268).
TOOLS
Standard
Standard set of hand tools.
Metric set of hand tools.
VOM with AC current tester (any quality VOM
with a sensitivity of at least 20,000 ohms can
be used).
Gear puller to remove cavity fan.
Temperature meter with thermocouple.
Special
Red High Temperature RTV for door seal and
probes (P/N 544313 or 542949).
Grounding kit to protect control board(s) if
handled (P/N TL-84919).
Motor Shaft Centering Tool (P/N 359450).
28 pin EPROM extraction tool and 28 pin
EPROM insertion tool (purchase locally).
Scalekleen deliming chemical or the
recommended chemical for the water treatment
system in use for deliming of the steam
generator. (Scalekleen is available through the
Service Parts Distribution Center or locally
through an Everpure dealer)