Frymaster H55 Series Technical Reference Manual page 51

A JIB (Jug in a Box) is shown being placed in a fryer
cabinet.
The ATO RTD (bottom in picture above) used in auto
fi ltering fryers is similar to the probe used in the H55
(top) and has the same resistance scale. However,
it is not interchangeable; it's much smaller. The low-
volume frypot probe uses a nut and ferrule.
An Automatic Top Off Board, or ATO, (see arrow)
monitors frypot oil levels and opens valves and runs a
top-off pump to move oil from a JIB to the low frypot.
The ATO board is housed behind the JIB along with
transformers and a relay related to the top-off system.
The McDonald's box may hold a LON board (eliminat-
ed in December 2014), a device for internal controller-
based monitoring of the complete fryer system. The
instructions for removal of the LON board are posted
online: 8197211.
Automatic Filtering Fryers
4-7
A 24-volt pump moves the oil from the
JIB to the frypots. The pump is accessi-
ble from the rear of the fryer. It is mount-
ed vertically or horizontally, depending on
the space available in the fryer cabinet.
If the hose is clogged and pressure
builds in the system, a 45PSI pressure
switch trips and prevents the pump from
running. The system can be checked by
removing the hose from the pump to see
if the pump resumes running.