© Panduit Corp. 2018
INSTRUCTION MANUAL
VeriSafe AVT
B21052_08
Page: 11 of 20
7-2018
Installation Considerations
This section provides guidelines for installing VeriSafe Absence of Voltage Testers (AVTs). It also addresses several common application
scenarios and describes best practices.
General Information
Before installing the AVT, identify all sources of electrical energy in the equipment. Install the AVT at the point in the circuit where you would
normally test for voltage. The AVT will only test for voltage at the point where it is installed. If there are multiple energy sources or multiple
test points, consider using multiple AVTs.
The AVT may be installed on the supply (line) or load side of an electrical disconnect. When the AVT is installed, mark the test location on the
yellow Instruction Label. Apply this label to outside of enclosure near the Indicator Module.
The Voltage Presence indicators only illuminate red when hazardous AC voltage is detected. The absence of voltage test will verify absence
of any voltage (AC and DC) before the Absence of Voltage Indicator is illuminated green.
The AVT is required to be solidly grounded and bonded to the protective conductor terminal of the enclosure. Review the Schematics section
of this Instruction Manual. Although the absence of voltage threshold is 3.0 V, residual voltages should be less than 1.3 V to ensure optimal
reliability.
When installing an AVT, care should be taken to ensure that Sensor Leads used to connect the AVT to the circuit conductors and to ground
shall not be any longer than necessary and shall be routed to avoid sharp edges, pinch points or mechanical damage. Do not extend the
sensor leads with a splice.
Always follow instructions in this Instruction Manual. Do not exceed specified environmental or performance limits.
Effect on Short Circuit Current Rating (SCCR)
AVTs listed to UL 1436 are required to operate as a secondary circuit that is isolated from the circuit conductors by use of a transformer,
optical isolator, or limiting impedance, or other similar means. This is intended to reduce the risks of both electric shock and thermal hazard.
These isolation circuits allow very limited current flow, if any, through the AVT.
The VeriSafe AVT is suitable for use on circuits delivering up to 300,000 rms symmetrical A at 600 V.
Use of Overcurrent Protection
Installation of overcurrent protection is not required for safe operation of the VeriSafe AVT. UL 1436 requires AVTs to be constructed so
that internal component failures will not expose the AVT to available short circuit currents from the main power supply during normal
operation and under single-fault conditions. The VeriSafe AVT Isolation Module uses high impedance to limit voltage and current flow
through the device to safe levels. In addition, the VeriSafe AVT has been tested to withstand transient overvoltage up to 6 kV. In the US,
the sensor leads of the AVT can be treated as a feeder circuit per NEC article 240.21(B)(1)(b) Exception (NFPA 70:2017). This rule allows a
tap of no more than 10 feet on a feeder circuit without the need for overcurrent protection.
Other local wiring codes and regulations may require use of overcurrent protection. Always follow applicable codes and standards when
installing the device. The VeriSafe AVT can be installed safely with overcurrent protection. When installing overcurrent protection with the
VeriSafe AVT, it is important to install one overcurrent protection device for each of the six sensor leads. Overcurrent protection should
not be installed with the two green ground leads.
Do not install multiple lead wires on one overcurrent protection device in a configuration
that would leave lead wire pairs electrically connected in the event that the overcurrent protection is in the open state.
