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©2021 Hubbell Incorporated | Chance® DC Hi-Pot Adapter Operating Instructions
Function and Design Overview
Features
The CHANCE® DC Hi-Pot Adapter is a valuable tool for locating faulted cable sections in an
underground loop. It is a simple, reliable tool that adds capability to the lineman’s existing
CHANCE® 5&16 kV or 16 kV Phasing Sets, allowing immediate cable testing following storm
emergencies and with new construction. The compact size and low cost, compared to other
available diagnostic cable testers, allows for multiple trucks to do cable testing without long
outages while waiting for more expensive and complicated equipment to arrive on the job site.
The DC Hi-Pot Adapter is designed for use with High Voltage cables consisting of a center
conductor surrounded by a properly rated insulating dielectric which has an outer concentric
conductive element. The construction of the High Voltage cable allows for a properly isolated
cable section to be charged by the DC Hi-Pot Adapter and then hold the charge if no leakage
path exists.
The principle behind the successful use of the DC Hi-Pot Adapter is the characteristic that a
properly isolated High Voltage URD coaxial cable will act as a capacitor that holds an electrical
charge unless a discharge path (fault) is present. When following all instructions, the diagnosis
of a “good cable” is one that shows a decreasing voltage differential between the source and
the cable under test. Once the cable reaches its maximum (capacitive) voltage charge, the
Phasing Set will show little if any voltage differential between the AC source and the isolated
cable under test. If the isolated cable under test is faulted, it will not be able to hold a DC
charge and the Phasing Set will show a voltage differential between the AC source and the
cable under test. A discharge path (fault) from the center conductor of the High Voltage URD
cable and the concentric neutral will be electrically evident when properly utilizing the DC Hi-
Pot Adapter.
Utilities have discovered that utilizing the DC Hi-Pot Adapter on Phasing Sets allows a safe,
silent, and non-damaging way to test the isolated cable condition before energizing. The
adapter is essentially a diode that converts the AC line voltage to a DC voltage.
Utilizing the DC Hi-Pot Adapter also limits exposure of the suspect cable section to additional
damage from high fault currents. The DC Hi-Pot Adapter is a compact unit that threads onto
the end of the Phasing Set by use of the 1/4” x 20 stud. Provisions include being able to safely
interface to the cable through use of bushing adapters and feedthroughs.
• Protects the cable under test from additional high fault current damage
• Does not require an upstream protective device to operate during the test
• Results can be determined silently without the loud report of the fuse operation
• Prevents blinking of lights and power surges due to faults that may be present on the
system
Utilizing the DC Hi-Pot Adapter:
The DC Hi-Pot Adapter was designed for use with the CHANCE® 16 kV Phasing Set (H1876).
Use the adapter with the proper voltage rating for your system.
NOTICE
The 35 kV DC Hi-Pot Adapter (C4031763) can be used on all High Voltage distribution
cables up through 35 kV. Likewise, two 16 kV DC Hi-Pot Adapters (C4031762) can be
stacked together and used on up to 35 kV systems.
NOTICE
