Safety Systems - Gaymar Medi-ThermTM II Manual Del Operario

Medi-Therm
TM

8.0 Safety Systems

8.1 Overtemp Safety Circuits
In the event of a controller failure, there are two separate
backup circuits which prevent the blanket temperature
from surpassing safe operating limits.
The first overtemp backup consists of an electronic
sensing circuit, totally independent of the main control
circuitry. This circuit will interrupt heater power and
initiate a REMOVE FROM USE NOW audible and visual
alert to keep the blanket temperature below 42°C. The
second overtemp backup is a bimetallic thermostat which
will directly interrupt power to the heater in the event
that both the main control circuitry and the first backup
fail. This device will also initiate a REMOVE FROM USE
NOW alert.
8.1.1 Overtemp Verification Test
Perform the following test to verify operation of
the first overtemp safety backup without having
to open up the machine. Refer to the Medi-Therm
II MTA6012CE Service Manual if complete service
testing of the machine is required.
1. Disconnect the hoses from the SUPPLY and RETURN
fittings on the front of the machine.
2. Turn the machine on while simultaneously pressing
the TEST LIGHTS button. This will put the unit into
a TEST MODE. In this TEST MODE, the blanket
temperature display will light, the set point will
display "0", and the temperature will start to
increase.
NOTE: If the unit flashes CHECK FLOW, the
hoses have not been disconnected
and the temperature will not increase.
Disconnect the hoses.
3. If the first overtemp safety circuit is working
properly, the unit should go into a REMOVE FROM
USE NOW alert condition. The audible indicator will
remain on continuously. The entire test should take
approximately 3 minutes.
If the unit goes into a REMOVE FROM USE NOW alert
condition, but the audible indicator does not remain
on, the first overtemp backup is not functioning and
the second overtemp backup has tripped. Do not use
the machine. Request service.
II
If the unit does not go into a REMOVE FROM USE
NOW alert condition, do not use the machine.
Request service.
4. Turn the machine off. This will end the TEST MODE.
5. Reconnect hoses to the fittings on the front of the
unit.
6. Turn the unit on and select BLANKET CONTROL
mode immediately. This will allow water to flow past
the first over-temp probe and reset it.
NOTE: If the machine goes into a REMOVE FROM
USE NOW alert condition again when selecting
BLANKET CONTROL, the second over-temp backup
device (the thermostat) has also tripped. Turn the
machine off. Connect a hose to the SUPPLY fitting.
Direct the other end of the hose into a water
container so that water from the cold reservoir
will siphon past the thermostat and reset it. Allow
water to flow for approximately two minutes.
Safety Systems
11