Thermo King UT-1200, Manual

Page: 81 / 169

Electrical Maintenance
81
Fuses
A number of fuses protect various circuits and
components. All the fuses except F21 are located
on the base controller, which is located inside the
control box. F21 is located in the fuse holder
between the REDB and 2 wires that go from the
battery to the 2 terminal on the base controller.
Refer to the appropriate Microprocessor
Diagnostic Manual for a complete list of the size
and function of the fuses.
Figure 148: Base Controller
Fuses
Fuse Size Function
F2 15A Power to On/Off Switch
F3 40A Fuel Sol Pull-In/Starter Circuit
F4 None
2A
No Fuse - All Bosch and Thermo
King Alternators
2A Fuse - All Prestolite Alternators
F5 40A Preheat Circuit
F6 15A Damper and High Speed Circuits
F7 2A 8XP Circuit - Controller On
Feedback to HMI
F8 5A 2A Power to CAN Connector J12
F9 5A 2A Power to CAN Connector J14
F10 10A 8X Power (Install fuse in right
position)
F11 10A Power to Drain Tube Heater Relay
for Remote Evaporator (Not Used)
F12 5A 2A Power to CAN Connector J13
F13 2A 8FC Circuit (Remote Status
Light/Optional Power)
F21 60A Main Fuse (2 Circuit)
F20 2A Alternator Sense
F25 7.5A HPCO/Run Circuit
F26 5A Power to CAN Connector J98
F4 Remove fuse F4 for units with Australian Bosch
or Thermo King Alternators. Install fuse F4 for units
with Prestolite Alternator.
F10 There are three in-line fuse clips that allow for
two configurations of the F10 fuse. The right position
is the normal position. This position has a white bar
below it on the circuit board. When fuse F10 is
installed in the right position, control power is routed
to the K9 On/Off Relay contacts. The On/Off keys on
the HMI Control Panel energize and de-energize the
K9 On/Off Relay. When the K9 On/Off Relay is
energized power is supplied through the normally
open K9 contacts to turn the unit on.
When fuse F10 is installed in the left position, power
bypasses the K9 On/Off relay contacts and the unit
will start and run without the HMI Control Panel
connected. Do not operate the unit with the F10 fuse
installed in the left position unless absolutely
necessary.
IMPORTANT: If fuse F10 is installed in the left
position the unit may start and run. If the HMI Control
Panel is connected the On and Off keys will still
function. The Off key will turn the unit off if Fuse F10
is in the left position, but the Base Controller will
remain powered up.
Fuses (Continued)