Issue:
How do we assess the Installation Styles of HEPDs?
Product Line:
Surge Protective Devices
Environment:
HEPD Whole Home Surge Protective Deveice
Resolution:
Listed below are the styles an HEPD can be installed and their ratings on how effective each are.
A. Direct Bus Connected
This is described in Figure 4 page 6 on the linked User Guide below. This is the most effective way to install the HEPD. It has the least conductor run among the installation types. But the major consequence for this installation is in replacing the SPD. The whole panelboard would have to be de-energize the whole panelboard just to disconnect and replace the SPD.
B. Dedicated Breaker (as near to the main as possible)
This is shown Figure 3 page 6 of the same document. This is second to effectivity and first for practicality. You can simply isolate the SPD with the branch breaker it is connected to in times of maintenance. It can then be tested with ease since the whole panel would not have to be de-energized.
C. Alternate Direct Bus Connection
Shown on Figure 5, left side. Though it is directly connected to the bus, there is a significant conductor run with the wire-leads being used on its full-length. Remember that the thinner the wire is, the more resistance it has. This causes the least effectivity on the SPD.
D. Alternate Dedicated Breaker Connection
Shown in Figure 5, right side. This is third on effectivity. The connections between the breaker and the bus bar have less resistance compared to when the wire leads are being used on their full length
Released for:Schneider Electric USA
