Potential For Electrical Shock - OPTICOM 764 Installation Manual

5.1 Potential for Electrical Shock

A potential exists for a low-current electrical shock (less than 4.5 mA) caused by leakage current in the
power supply section of the phase selectors. You may experience this low-current shock when you touch
the front of the phase selector, when you insert the phase selector into its slot in the input file, or when you
remove the phase selector from its slot.
You can minimize this shock potential by making sure that pin L of the card edge connector in the 170 type
controller input file is grounded properly to earth ground. If pin L is not connected to earth ground, your
risk of exposure to this shock potential increases.
Use the following procedure to verify that pin L is connected properly to earth ground.
WARNING
This procedure may expose you to AC
voltage and the risk of electric shock or
electrocution. Turn off the AC mains and
use accepted and recognized safety
precautions to avoid exposure to the risk of
electric shock or electrocution. Electric
shock may cause severe injury or death.
1. Turn off AC power to the input file.
CAUTION
This procedure must be performed in an
Electro-Static Discharge (ESD) free
environment. Failure to perform this
procedure in the proper environment may
damage the equipment.
2. Remove the phase selector from the input file slot and place it in a static-free bag. Do this for all phase
selectors in your system.
3. Locate pin L on the 44-pin edge connector of each phase selector slot and verify continuity to earth
ground. See Figure 5-1.
a) Set an ohmmeter to its lowest resistance scale.
b) Measure the resistance between pin L and earth ground. If the resistance is less than 5 ohms, pin L
is grounded properly.
4. If the resistance is greater than 5 ohms, inspect the input file wiring and repair and/or replace as
necessary to correct the problem. Then retest the resistance.
Intersection Equipment Installation Instructions
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