standards and guidelines for communication sites - Radio And ...

AC POWER SPD REQUIREMENTS CHAPTER 7: SURGE PROTECTIVE DEVICES
Electrical meter and main
service disconnect are
located on the cabinet
exterior, an adjacent
pedestal or utility pole.
See Notes 1 & 2
Main Service
Disconnect
Meter
Utility Feed
AC
240/120 Single Phase
NOTES:
To Alarms Panel
(Recommended)
SPD
(Surge Suppressor)
Type 1 (SAD/MOV)
Utility
Panelboard
See Note 2
Non-Critical
Loads
Type 3 SPD optional when greater
than 10 conductor feet from
panelboard.
To Alarms Panel
1. The main service disconnect may be located outside the pole or pad mounted equipment cabinet, typically on the cabinet
exterior, an adjacent pedestal or utility pole.
2. The main service disconnect may be an integral part of the Utility Panelboard.
3. The UPS may not be present in which case all loads will be fed from the Utility Panelboard
4. The Type 1 SPD shall be installed per the manufacturer's installation instructions.
5. All conductors between the SPD and the associated disconnecting device shall be as short as possible and routed together
with a minimal number of bends or angles of less than 90 degrees.
6. The SPD disconnecting device should be installed in the top most space available in the Utility Panelboard.
7. Installation of Type 3 SPDs on critical and non critical loads, although optional, is recommended where the level of
exposure is high.
FIGURE 7-15 SPD INTERCONNECT BLOCK DIAGRAM ‘N’
Pole or Pad mounted equipment cabinet(s)
UPS
See Note 2
UPS
Panelboard
Type 3 SPD
optional
Critical
Loads
7-24 68P81089E50-B 9/1/05