User Manual

Lightning Protection
142
11.4 Locating the Fault
Having identified which of the wiring cores are likely to be connected incorrectly, the location of
the faulty cable can be narrowed by disconnecting sections of the drop cable and by unplugging
the relevant RJ45 connectors from the LPUs.
As a further aid to locating the fault the Ethernet connections are also available inside the LPU.
The connections can be accessed by rotating the LPU lid as shown in Figure 99 The Lid nut only
needs to be slacken, do not remove. Test point P1 on the LPU PCB corresponds to pin 1 on the
RJ45 etc.
An indication of power on the Ethernet cable is also provided inside the LPU, LED PWR1 will
illuminate in the case of the PTP600 series, LED PWR2 should not.
Figure 99 PTP LPU test Points