Advanced Protection TWL User Manual
Page 2
WARNING – IMPORTANT – PLEASE READ – WARNING
Safety First – Hazardous Voltage & Shock Hazard
• Only qualified licensed electricians should install or service SPDs
• Hazardous voltages exist within SPDs
• SPDs should never be installed or serviced when energized
• Use appropriate safety precautions including Personal Protection Equipment
• Failure to follow these instructions can result in death, serious injury, and/or equipment damage
• This manual shall be read in entirety prior to installing
Bonding and Grounding Hazard
Verify that the neutral conductor in the AC voltage service entrance equipment is bonded to ground in accordance
with guidelines established by the National Electric Code (NEC
®
). This is intended to provide the power system with
a defined reference to ground.
There may be circumstances where the Authority Having Jurisdiction (AHJ), for example, a DOT, supercedes the NEC
and or local codes. We caution that deviations from North American, industry-accepted bonding & grounding and surge
suppression techniques may yield undesirable and unexpected results.
Verify that the neutral terminal (XO) on the secondary side of distribution transformers are grounded to the system
ground in accordance with the NEC
®
and all applicable codes.
During installation into an electrical system, the SPD must not be energized until the electrical system is completely
installed, inspected and tested. All conductors must be connected and functional including the neutral (if required).
The voltage rating of the SPD and system must be verified before energizing the SPD.
Failure to follow these guidelines can lead to abnormally high voltages at the SPD. This may cause the SPD to fail. The
warranty is voided if the SPD is incorrectly installed and/or if the neutral conductor in the service entrance equipment
or downstream of separately derived systems is not bonded to ground in accordance with the NEC
®
.
Do Not Hi-Pot Test SPDs
Any factory or on-site testing of power distribution equipment that exceeds normal operating voltage such as high-
potential insulation testing, or any other tests where the suppression components will be subjected to higher voltage
than their rated Maximum Continuous Operating Voltage (MCOV) must be conducted with the SPD disconnected from
the power source. The neutral connection at the SPD must also be disconnected prior to performing high-potential
testing and then reconnected after test completion.
Failure to disconnect SPD and associated components during elevated voltage testing will damage the SPD and will
void the warranty.
(APT is unaware of any SPD manufacturer that permits Hi-Pot testing of SPDs.)