Unit installation

Troubleshooting and Maintenance
974-24007001/4.1 75
Example:
The TTM output DC voltage is set at 200 VDC.
The Cable Voltage at the head is 192.7 VDC
Total DC voltage drop along the 3
rd
wire cable is 7.3 VDC.
The TTM AMP meter located on the front panel indicate a current
of 0.3 A. Therefore the calculated total resistance of the 3
rd
wire
cable is:
R =
–
The maximum allowable closed loop cable resistance is 100 ohms.
5.4.5.3 Test for Water Ingress in the Trawl Cable
When a trawl cable is damaged or there is a poor splice, sea water
can get into the cable. As a result, the cable may act as a battery -
producing a small dc voltage across the conductors of the cable.
This is detrimental to the operation of the FS system and all
affected cable should be removed.
To test for this the trawl cable should be disconnected from the FS
system and a voltage meter connected to the trawl unit end of the
cable. If water is present, then there may be a reading of 2 - 3 volts.