Service; Troubleshooting; Latch Assembly - Thermo IEC 448 Manual De Operación

5

SERVICE

5.1

Troubleshooting

If the unit will not start, check the following in order to isolate the
problem:
• Check the fuse by removing the base of the unit.
• Check the resistance across the coils of the relay, which is approximately
3.5 kΩ.
• Check the latch microswitch and the proximity switch.
There are two switches in the unit. One is the latch switch and the other is
the proximity switch. Both are in series with the relay and must be
'closed' in order for the unit to operate.
To access the components, unplug the centrifuge, open the cover, and
remove the rotor. Carefully place the unit upside down on its cover and
remove the four bolts (1/4 inch socket) which secure the baseplate. Lift
the baseplate off.
5.2

Latch Assembly

The latch assembly consists of a catch, a striker, a microswitch, and a
proximity switch. When the cover is closed, the cover striker engages the
microswitch, which senses the status of the cover (open, closed/locked).
The proximity switch also senses the position of the cover for the purpose
of disabling a run unless the cover is fully closed. The proximity switch
magnet is located in the cover and causes the switch located in the cabinet
to actuate.
To remove the latch switch, remove the two Phillips head screws at the
front plate of the unit. Note the wiring to the switch and disconnect.
Medilite Operation Manual
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