Operation Manual
MELA
quick
®
12
Page 22
8.2.6 Too much loss of water __________________________________________________________
In this case, the water pump runs several times
after the start of the program.
Fault diagnosis:
After a program start, the autoclave ventilates the
chamber through the flow nozzle which is screwed
into the measuring block (see also chapter 8.2.1).
Then steam constantly flows through this jet into the
condenser container. The resulting loss of water is
equalized by the amount of water supplied to the
steam generator at the beginning of a process. If
water gets lost beyond, this can happen due to
enlarged flow nozzle, leak in the chamber seal (see
also 7.9) or at the solenoid valve, the safety valve or
due to a loose coupling.
If the steam generator is calcificated due to bad
water quality, the pump will also start again because
the overheat protection of the steam generator re-
leases before heat reaches the water inside.
The pump will start again at release of the steam
generator's overheat protection and after the end of
the real pumping time. Thus, the correct supervision
times for pressure generation and killing may be
exceeded.
Call for a service engineer.
1. If a loud hissing sound can be heard at the
sliding door while the autoclave is under
pressure, or if the indicator instruments are
fogged, then the cause is one of the following:
either the gasket lip has been turned over by
improper closing of the sliding door, or the gasket
for the pressure chamber is defective.
2. Otherwise, loosen the connection of the hose
from the pump to the chamber block, bend hose
into a measuring beaker without kinking it and
start the pre-warmed apparatus. After
16 seconds, the pump must stop with an amount
of raised water between 130 and 170 ml.
Alternatively, you can measure the weight of the
condenser container before and after
sterilization. The increase of weight must be 130-
170g.
If there are deposits of scale on the top side of
the disassembled hose, then it is necessary to
clean both this hose as well as the steam
generator. See Section 8.2.7.
Fault correction:
1. The gasket of the sliding door must be cleaned or
replaced (see Section 2.3).
2. If the amount of water is too small, refer to
Section 1.1.1.
If the amount is correct, optically check all joints
for leakage when they are under pressure. Watch
the water discharge hose of the solenoid valve
(short and straight Teflon hose from solenoid
valve to a hose-T-junction, left side of the
apparatus). Here, no steam should flow. Observe
discharge hose of the safety valve (bent Teflon
hose from ground plate to hose-T-junction, right
side of the apparatus). Here, no steam should
flow.
Tighten all joints, clean or replace solenoid valve
or clean safety valve (replace inner parts of it).
If there are no such leakages, check the flow
nozzle and perhaps replace it. The diameter of
the orifice must not be much larger than 0.5 mm.
If the problem is still not solved (but water supply
is okay, no water loss) and the pressure
generation operates slower than usual, check the
steam generator for calcification. It must be
cleaned or changed.
8.2.7 Steam generator is clogged with boiler scale ________________________________________
In this case, the feed water pump runs several
times after the start of the program.
Fault diagnosis:
The feed water pump (47) starts several times,
although amount of the water is sufficient (see
Section 1.1.1), and although there are no leaks (see
8.2.6). In addition, the upper side of the hose from
the feed water pump (47) to the chamber block (37)
is covered with scale.
You must notify the MELAG Customer Service
Department.
Correction of the fault:
The hose and the steam generator must be cleaned
or replaced if required.
8.3
Fault No. 5 ______________________________________________________________
Cause of the fault:
After the autoclave has once achieved the
sterilization or disinfection parameter for pressure
and temperature (as shown by the signal lamp
„
RUNNING“ (12) shining continusly), the system is
not able to maintain these parameters for the
required period of 4 minutes for sterilization, or 6
minutes for disinfection, throughout the monitoring
period of 5.5 minutes for sterilization, or 7.5 minutes
for disinfection.
Time when the malfunction occurs:
After the start, and after 5.5 minutes (for sterilization)
or after 7.5 minutes (for disinfection) after once
achieving the sterilization or disinfection parameters
for pressure and temperature (as shown by the
signal lamp
„
RUNNING“ (12) shining continuously).
The cause here can be as follows:
