Section 8.Theory of OperationModel 6210 Maintenance Manual

Definitions

Short-Circuit or Short

A short circuit is an unspecified path in a circuit that provides unwanted full or partial continuity between two or more locations in an electrical circuit.

Example 1: Two insulated wires are physically next to each other and the insulation has worn off each of the wires. The conductors are now touching each other, causing a short circuit.

Example 2: A power cable from the battery to a junction post in the truck has had the insulation worn away. Because the wire conductors are touching the tractor frame, there is a short circuit of the battery cable.

Speed Limiting

The Vehicle Manager limits the maximum speed. The “Max speed, Walking Mode” parameter determines the maximum speed value sent by the VM to the traction amplifier (max. PWM) for the two directions of travel while in travel mode. This is a programmable parameter.

Thermal Cutback (Traction Amplifier)

Thermal cutback of the traction amplifier is below –13°F (–25°C) or above 185°F (85°C). At 185 to 203°F (85 to 95°C), the drive current limit is linearly decreased from full set current down to zero. At –13 to –40°F (–25 to –40°C), the current limit is reduced to approximately half the set current, resulting in reduced travel speed. Below –40°F (–40°C) or above 203°F (95°C), the allowed travel speed is zero percent. This function sets code C43 on the display when a thermal cutback condition occurs. It may also be a factor when codes C44 and C46 occur.

Tractor

The body section of the truck that contains the motors, drive unit, controls, and handle.

Truck Off Delay (Keypad only)

This delay sets the truck OFF delay time (energy saving feature). If this time delay passes while the truck is in a brake position and the truck is idle (no inputs requested), the Vehicle Manager powers the truck OFF. This is a programmable Driver parameter setting that ranges from 0 to 20 minutes. When the para meter is set to 0, or the truck has the key switch, the truck never powers OFF.

Undervoltage Cutoff

Undervoltage protection automatically occurs when there is very low voltage (less than 13V) at the traction amplifier TA B+ connection. Code C41 is displayed and the truck must be restarted.

Vehicle Manager

Programmable motor control functions are performed by the electronic circuitry (VM) housed within the control handle.