TM 10-8145-222-23
0003
INSULATED CONTAINER CONTINUED
When external power is selected by the operator as the power source to operate the MTRCS refrigeration unit, the
diesel engine will not be operational and only the electric motor in the refrigeration unit is operated. Power from the
selected external power source will be input to the Power Box Assembly based on the hook up requirements of
Table 1. The external power is routed through the Power Box Assembly, to the Motor Controller (MC) relay, which in
turn directs power to the electric motor and control box. The MTRCS electrical schematic (Figure FO-1) provides
additional illustrative detail about MTRCS power control and distribution.
If the integral diesel engine is selected as the power source for the MTRCS refrigeration unit, no external electrical
connection is required.
Control Box Assembly
The Control Box Assembly (Figure 3) is a two sub-component assembly consisting of the Control Panel and
Microprocessor Controller Display (MCD) (Figure 4), and is accessible from the exterior of the MTRCS unit. The
Control Box Assembly is enclosed within a watertight, heated, and electro-magnetic interference (EMI) shielded box.
The box is equipped with a trap drain on the bottom that provides drainage of any moisture or liquid that may form or
leak into the box. The control box portion of the assembly is located on the upper half and includes three toggle
switches for normal or blackout mode selection; compartment 1, 2, power on/down switch, compartment 1 and 2
over/under temperature audio alert signals with corresponding indicator lights; and two fuel level indicator lights for
good (green) and low (red) fuel level indication. The bottom portion of the assembly consists of the MCD.
The Control Box, used in conjunction with MCD located at the bottom of the Control Box Assembly, will enable the
diesel engine startup. Additionally, various operating parameters can be set and warnings can be given through the
microprocessor control during operation.
Figure 3. Control Box.
