Pitco AG14S-C Service Manual
Service Manual
ADVANCED GAS FRYER with FILTER
PITCO MODEL AG14S-C
MANUF ACTURED
BY
P.O.BOX 501
CONCORD, NH 03302-0501
PHONE: 1(603)225-6684
for the
CE Market Only
Pitco Frialator
Literature # L20-172 Rev 1 Rev Date 28 February 2001 Made in the United States of America
FOR YOUR SAFETY :
Do not store gasoline or other flammable
vapors or liquids in the vicinity of this or
any other appliance.
WARNING
There is an open flame inside the machine. The
unit may get hot enough to set nearby materials on
fire. Keep the area around the unit free from combustibles.
TO THE PURCHASER
POST IN A PROMINENT LOCATION INSTRUCTIONS TO BE FOLLOWED IN THE
EVENT THA T AN OPERA TOR SMELLS GAS.
OBT AIN THIS INFORMATION FROM YOUR
LOCAL GAS SUPPLIER.
WARNING:
IMPROPER INST ALLA TION, ADJUSTMENT ,
AL TERA TION, SERVICE OR MAINTENANCE
CAN CAUSE PROPERTY DAMAGE, INJURY
OR DEA TH. READ THE INST ALLA TION, OPERATING AND MAINTENANCE MANUALS
THOROUGHLY BEFORE INSTALLING OR
SERVICING THIS EQUIPMENT.
WARNING
This appliance is equipped with a grounding plug.
This is for your protection against shock hazard in
the event of equipment malfunction. Always plug
the unit into a properly grounded receptacle. DO
NOT cut or remove the grounding prong.
WARNING
DO NOT use an open flame to check for gas leaks!
Keep all open flames away from the machine at
all times.
WARNING
Machines equipped with casters and a flexible
power cord, must be connected to a gas supply
with a Quick-Disconnect device. This quick disconnect must comply with all local and national
codes. To limit the movement of the unit without
depending on the connector or quick disconnect,
a restraining device must also be installed.
WARNING
DO NOT supply the fryer with a gas that is not identified on the data plate, located on the inside of one
of the doors of the machine. If you need to convert
the machine to another type of fuel, contact your
dealer or Authorized Service Agency .
WARNING
Ensure that the machine can get enough air to keep
the flame burning correctly. If the flame is starved
of air it can give off a dangerous carbon monoxide
gas. Carbon Monoxide is a clear odorless gas that
can cause suffocation.
WARNING
Carbon Monoxide gas can build up if you obstruct
the flue. Blocking the flue will also cause the unit
to overheat. DO NOT obstruct the flow of combustion/ventilation or air opening around the machine. Ensure that you meet the minimum clearances specified in the installation instructions.
Adequate clearance around the unit is necessary
for servicing and proper burner operation.
WARNING
If the machine should shut down unexpectedly wait
5 minutes before attempting to restart it. This will
allow for any excess gas in the unit to dissipate.
WARNING
The power supply must be disconnected before
servicing or cleaning the unit.
W ARNING
T o prevent tipping of the machine and splashing of
HOT oil your Pitco Frialator fryer is equipped with
a Gas Hose Quick Disconnect and restraining device. This attaches the rear of the machine to the
wall. When the fryer is in its operating location, lock
the casters and reattach the restraining device to
the rear of the machine.
WARNING
Shortening, when it is at cooking temperatures, is
very HOT and DANGEROUS! Use extreme caution when handling! Use the proper protective gear
such as insulated gloves, aprons, face shield and
sleeves when handling hot shortening. DO NOT
attempt to move any machine that has hot oil in it.
Allow the oil to cool to room temperature or drain
the oil into a suitable container before moving the
fryer.
Table of Contents
T able of Contents ....................................................................................................... i
Chapter 1: HOW DOES IT WORK? ......................................................................... 1
Heating System - Full T ank ..................................................................................... 1
Heating System - Split T ank .................................................................................... 1
Hi - Limit System..................................................................................................... 2
Filter System ............................................................................................................ 2
Chapter 2: COMPONENT TROUBLESHOOTING .......................................................... 3
Probe ....................................................................................................................... 3
Relays ...................................................................................................................... 3
Hi Lim its .................................................................................................................. 3
Drain Valve & Return Valve Switches.................................................................... 3
Transformer ............................................................................................................. 3
Blower ..................................................................................................................... 4
Pressure Switch ....................................................................................................... 4
Gas Valve................................................................................................................. 4
A note on excessive air velocities within hood systems .......................................... 4
Chapter 3: TROUBLESHOOTING GUIDE ....................................................................... 5
Fryers....................................................................................................................... 5
Filters ....................................................................................................................... 6
Chapter 4: COMPONENT CHANGEOUT ........................................................................ 7
Probes...................................................................................................................... 7
Hi Lim its .................................................................................................................. 7
Computers ............................................................................................................... 7
Components mounted in the front panel .................................................................. 8
Filter Relays............................................................................................................. 8
Control Relays ......................................................................................................... 8
Filter Pumps............................................................................................................. 8
Circuit Breaker ........................................................................................................ 8
Gas Valves ............................................................................................................... 9
Burners and Spark Ignitors ...................................................................................... 9
Proximity Switches .................................................................................................. 9
Blowers.................................................................................................................... 10
Pressure Switches ................................................................................................... 10
Fry Tanks ................................................................................................................. 11
Chapter 5: Parts .................................................................................................................... 13
Operational Components ......................................................................................... 13
Filter ......................................................................................................................... 13
Miscellaneous .......................................................................................................... 13
Wiring Harnesses..................................................................................................... 14
Chapter 6: Parts Identification .............................................................................................. 15
Chapter 7: Schematics .......................................................................................................... 16 - 17
i
ii
Chapter 1: HOW DOES IT WORK?
The McDonald's Gas fryer will have certain reactions to what is happening, knowing what these reactions are and knowing what the machine is trying to
do will enable us to diagnose most of the problems
likely to be encountered.
Heating System - Full T ank:
· Power to the machine is turned ON:
· The computer is supplied with 24 VAC and, if
the Drain Valve Handle is closed, the Proximity
Switch will supply 24 VAC to the DVI (Drain
V alve Interlock) Input at the computer . The Ignition Control Modules are also supplied with 24
VAC at the 24V terminal.
· The computer is turned ON -
· Computer calls for heat and supplies 24 VDC to
the Heat Demand Relay which will energize supplying the Blower, the Pilot Solenoid on the Gas
Valve and the Pressure Switch with Power.
· The Pressure Switch will energize the Check
Blower Relay which will stay energized.
· When the Blower reaches its normal speed it will
cause the pressure switch to close supplying 24
VAC to the second set of switch points on the
Check Blower Relay . Because the Check Blower
Relay is still energized the power will be supplied to the TH terminal of each Ignition Control
Module.
· Both Ignition Control Modules supply power to
the Spark Ignitors. At the same time one of the
Ignition Control Modules supplies power to the
Main Valve Relay coil. The other Ignition Control Module supplies power to the switch points
of the Main V alve Relay.
· The Main V alve Relay energizes allowing the second Ignition Control Module to supply power to
the Main Solenoid of the Gas Valve.
· At this point the main burners will ignite. This
will also supply the computer with a heat feedback signal. (It is the lack of this Feedback signal that causes the Computer to display "Ignition
Failure".)
· Each Ignition Control Module will spark for 10
seconds and then check for a flame sense signal
from the Flame Rod. If the Ignition Control Module does not see a flame sense signal it will "Lock
Out".
Heating System - Split T ank:
· Power to the machine is turned ON:
· The computer is supplied with 24 VAC and, if
the Drain Valve Handle is closed, the Proximity
Switch will supply 24 VAC to the DVI (Drain
V alve Interlock) Input at the computer . The Ignition Control Modules are also supplied with 24
VAC at the 24 V terminal.
· Computer calls for heat and supplies 24 VDC to
the Heat Demand Relay which will energize supplying the Blower Relay and the Pressure Switch
with power. When the Blower Relay energizes
the Blower will be supplied with power and will
increase in speed until the pressure switch closes.
· Before the pressure Switch closes it will supply
power to the Check Blower Relay which will
remain energized.
· When the Pressure Switch comes up to speed it
will supply power to the second set of switch
points on the Check Blower Relay. Because the
Check Blower Relay is energized the Blower OK
Relay coil will be supplied with power causing
it to energize. When the Blower OK Relay energizes, one set of its Switch points supplies voltage to the Left Hand Ignition Control Module at
the TH terminal and the other set of switch points
supplies the right hand Ignition Control Module
with power at the TH terminal. The same power
that is supplied to the TH terminals of the Ignition Control Modules is also supplied to the Hi
Limit switches which, if closed, will supply
power to the Pilot Solenoid of the Gas Valve.
· When an Ignition Control Module is supplied with
power at the TH terminal it will supply power to
the Ignitor, the Main Solenoid of the Gas Valve
and the Heat Feedback Input of the Computer . (It
is the lack of this Feedback signal that causes the
Computer to display "Ignition Failure".)
· The Ignition Control Module will continue to
spark for 10 seconds and then look for a flame
sense signal from the Flame Rod. If the Ignition
1
Control Module does not see a flame sense signal it will "Lock Out".
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. 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 begin to pump. Closing the Return V alve Handle
will de - energize the Relay and the Pump will stop
pumping.
2
Chapter 2: COMPONENT
TROUBLESHOOTING:
Probe:
The resistance of the probe will change as the temperature changes. The resistance will decrease as the
temperature 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 RESIST ANCE TEMP RESIST ANCE
ºF Ohms ! ºF Ohms !
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 Normally 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.
60 139055 ! 330 1192 !
80 84644 ! 335 1123 !
100 53146 ! 340 1058 !
120 34328 ! 345 998 !
140 22755 ! 350 942 !
160 15446 ! 355 890 !
180 10716 ! 360 841 !
200 7586 ! 365 795 !
210 6427 ! 370 752 !
220 5470 ! 375 712 !
240 4013 ! 380 675 !
260 2991 ! 385 640 !
280 2262 ! 390 607 !
300 1734 ! 395 576 !
320 1347 ! 400 547 !
325 1267 !
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 operate 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.
WARNING
Do NOT leave the machine during this test. This
test will cause the oil to heat past the normal operating temperature and can cause damage to the machine 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 approximately 400°F (204ºC). If the switch
does not reset it is defective.
Drain V alve & Return Valve Switches:
This switch is a magnetically operated Reed switch.
When the Drain Valve handle is moved to the open
position, the Actuator will move away from the switch
causing the Reed switch to open. When the Drain
Valve is closed the Reed switch will close. This
switch can also be checked with an Ohm meter. The
normal gap between the Actuator and the Sensor
switch on the Drain Valve handle is 1/8" - 1/4" (3 - 6
mm).
Transformer:
Transformers are multiple input voltage, 24 volt output voltage and can be checked by reading the input
and output voltages.
3
Blower:
Check the voltage between the wires going to the
Blower. If voltage is found and the Blower is NOT
turning it is defective.
Pressure Switch:
As the blower speed rises the amount of vacuum on
the suction side of the pressure switch rises past approximately 1.3" WC (0.325 kPa) the Presssure
Switch will close. When the vacuum falls below approximately 0.8" WC (0.2 kPa) the Pressure Switch
will open. With the Blower running, check the IN
and OUT voltage of the Switch. If 24VAC can be
found on one side but NOT the other the Pressure
Switch is defective.
Gas Valve:
The Knob should be in the ON position. Check for
24VAC between the terminals marked MV and MV/
PV and between PV and MV/PV. If voltage IS found
between both of these connections and the Gas V alve
does not open the Gas Valve is defective. If voltage
is NOT present at both of the coils on the Gas V alve,
troubleshoot and repair the machine until voltage IS
present at both coils, retest the Gas Valve as previously described.
A note on Excessive Air V elocities within Hood
systems:
Extended recovery times and flame outage problems
may occur if Hood Air Velocities are excessively
high.
The baffle should be installed in the position shown
in the picture, using two self drilling screws.
4
Chapter 3: TROUBLESHOOTING GUIDE
Fryers:
It is assumed that, before starting any troubleshooting, the power is turned on and the gas lines are connected
correctly.
PROBLE M PROBABLE CAUSE CORRECTIVE ACTION
Computer does not come on A. Main circuit breaker is turned off A. Locate the correct circuit breaker and
nothing shows in either display B. Fryer fuse is blown turn OFF and back ON again.
C. Transformer B. Check and Replace as needed
C. Check Transformer
Computer heat light comes on A If the oil is hot the Hi Limit may be A. Allow the oil to cool, the Hi Limit will
but burners do not heat tripped reset when the temperature falls. Turn
the computer OFF and back ON again.
Press the reset switch.
Heat Light ON, burners not A. Heat Demand Relay A. Check Heat Demand Relay.
lit. B. F 2 Fuse ma y be blown B. Check and re p lace as needed.
C. Blower C. Check and replace as needed.
D. Pressure Switch D. Check and replace as needed.
E. Gas Valve E. Check and replace as needed.
F. Ignition Module (One or both) F. Check and replace as needed.
G. Gas Valve Relay (Full Tank Only) G. Check and replace as needed.
H. Tripped or defective Hi Limit H. Allow the oil to cool, the Hi Limit will
reset when the temperature falls. Turn
the computer OFF and back ON again
to reset the computer. Press the reset
switch. Check and replace is needed.
No Spark heard, blower IS A . Heat Demand Relay A . Check and replace where needed.
running B. Ignition Control Module B. Check and replace where needed.
C. Spark Ignitor C. Check and replace where needed.
Spark sound can be heard, A . F2 fuse blown A . Check and replace where needed.
Blower NOT running B. B lo we r B. Check and replace where needed.
C. Heat Demand Relay C. Check and replace where needed.
Spark sound can be heard, A . Ignition Control Module A . Check and replace where needed.
Blower IS running but main B. Gas V alve Relay (Full Tank Only) B . Check and replace where needed.
burners do not run C. Bad Pressure Switch C. Check and replace where needed.
D. Tripped or defective Hi limit D. Check and replace where needed.
E. Gas Valve E. Check and replace where needed.
Burner comes ON for short A. Flame Sensor A. Check and replace where needed.
time, does not come back on B. Ignition Control Module B. Check and replace where needed.
C. Gas Valve C. Check and replace where needed.
5
Filters:
PROBLEM PROBABLE CAUSE CORRECTIVE ACTION
Red Return Valve is open but no A. Red Return Valve NOT fully open A. Pull slightly on the Red handle to check
pump sound can be heard B. Filter Circuit Breaker may be tripped that it is fully open.
C. Filter Motor Thermal Overload may B. Locate the circuit breaker and reset.
be tripped C. Push Red reset button located on end
D. Sensor switch may be loose or bad of filter motor.
D. Check that the switch is tight in its
mounting. If switch is bad replace it.
Drain valve is closed and the A. Green Drain Valve is NOT fully A. Apply a little more pressure to the
computer has been reset but Closed Green Handle to check that it is
still shows "DRAINING" or B. Sensor switch may be loose or bad fully closed.
"TURN OFF" B. Check that the switch is tight in its
mounting. If switch is bad replace it.
Drain Valve is OPEN, the oil A. Green Drain Valve is NOT fully open A. Apply a little more pressure to the
is draining slowly or not at all. B. Drain is plugged with debris Green Handle to check that it is fully
closed.
B. Use the Clean Out Rod from inside the
Fry T ank to clear the Drain V alve. If this
NOT clear the blockage, CLOSE the
Green Drain Valve and follow these
instructions for clearing the main drain
line.
CAUTION:
Some HOT oil may still come out when
the cap is removed.
Remove the two screw from the end
cap (Do NOT lose these.) Use the
Clean Out Rod to clear the main drain
tube. Install the end cap along with its
gasket and two screws. Do not
overtighten these screws.
6
Chapter 4: COMPONENT CHANGEOUT :
It is assumed that for all (except ehere noted) of these
component changeout instructions the fryer has been
shut down and disconnected from the power and gas
supplies, cooled and drained of oil.
Computers:
CAUTION
T ake care not to drop any of the components from
the front panel as this will damage them.
Probes:
1. Unplug the wiring connector.
2. Unscrew the small nut on the probe seal.
3. Slide the probe from the seal.
Install in the reverse order using the new ferrule supplied with the new probe.
Hi Limits:
1. Unplug the wiring connector.
2. Unscrew the Hi Limit from the front of the fry
tank.
1. Remove the two screws from the upper mount of
the front panel.
2. Unplug the wiring connector at the rear of the
computer.
NOTE: On split tank machinesyou will find 2 wiring connectors to unplug.
Install in the reveres order.
Install in the reveres order.
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