Hi - Limit System; Filter System; Chapter 2: Component Troubleshooting; Probe - Pitco frialator MG14S-C/MFD Serviceanleitung

Hi - Limit System:

When the Hi Limit trips it causes the power to the Pilot
Solenoid to stop and gas will cease to flow through the
gas valve. This will cause a Lock Out condition and the
computer will show "IGNITION" "FAILURE". The Hi
Limit is an automatic reset type switch. In order to make
the computer recognize that the Hi Limit has reset it must
be turned OFF. The reset switch must be pressed and
released in order to reset the Ignition Control Modules
and the computer turned back ON again for further use
of the fryer.

Filter System:

Opening the RED Return Valve Handle will cause the
Pump On Relay to be energized and the pump will be-
gin to pump. Closing the Return Valve Handle will de -
energize the Relay and the Pump will stop pumping.
Chapter 2: COMPONENT
TROUBLESHOOTING:

Probe:

The resistance of the probe will change as the tempera-
ture changes. The resistance will decrease as the tem-
perature rises. The lower the temperature the greater
the resistance change will be per degree of temperature
change, as the temperature approaches the working
range of the probe, the resistance change will become
more linear.
If the probe is suspect, check its resistance and the oil/
air temperature at which it was taken. Compare these
values on the chart below.
TEMP RESISTANCE
Ohms Ω
ºF
139055 Ω
60
84644 Ω
80
53146 Ω
100
34328 Ω
120
22755 Ω
140
15446 Ω
160
10716 Ω
180
7586 Ω
200
6427 Ω
210
TEMP RESISTANCE
Ohms Ω
ºF
1192 Ω
330
1123 Ω
335
1058 Ω
340
998 Ω
345
942 Ω
350
890 Ω
355
841 Ω
360
795 Ω
365
752 Ω
370
4
5470 Ω
220
4013 Ω
240
2991 Ω
260
2262 Ω
280
1734 Ω
300
1347 Ω
320
1267 Ω
325
If the probe returns an open circuit or 0 Ohms reading it
should be replaced. If the resistance varies more than
20 Ohms from the above chart when being checked
between 325-375°F (162ºC - 190ºC) the probe will
give a false temperature reading on the computer and
should be replaced. However, it will continue to oper-
ate at a slightly higher or lower temperature. Allow the
oil to cool and check the probe resistance at a lower
temperature. As can be seen from the chart a greater
degree of offset can be allowed at a lower temperature.

Relays:

The Heat Demand relays are 24VDC relays and will
energize when the correct voltage is supplied to the
coil. When energizing, the relay Switching Contacts
will close, thus connecting the Common and Nor-
mally Open terminals. The Hi - Limit relay is a 24VAC
relay and may be checked in the same manner as the
above relay.

Hi Limits:

A Hi - Limit switch is a normally closed switch until
the temperature at the probe reaches 435ºF ± 15°
(225ºC ± 15º). In order to test this switch it will be
necessary to bypass the Heat Demand Relay. Follow
the Hi Limit testing procedure outlined in the Operating
Manual.
WARNING
Do NOT leave the machine during this test. This
test will cause the oil to heat past the normal operat-
ing temperature and can cause damage to the ma-
chine and its operator.
If the switch does not trip between the prescribed limits
it is defective and should be replaced. Once tripped, the
switch will not reset until the oil has cooled to approxi-
mately 400°F (204ºC). If the switch does not reset it is
712 Ω
375
675 Ω
380
640 Ω
385
607 Ω
390
576 Ω
395
547 Ω
400