Specialty Concepts LPU - Manual

L
IGHTNING
P
ROTECTION
U
NIT
(
LPU
)
Photovoltaic Lightning Protection Device
Installation and Operation Manual
S PECIALTY C ONCEPTS, I NC.
8954 Mason Ave.
Chatsworth, CA 91311 USA
MODELS COVERED: LPU-50, LPU-150, LPU-200 Copyright 6/1996 Specialty Concepts, Inc.
GENERAL DESCRIPTION
The Specialty Concepts Lightning Protection Unit (LPU) provides primary (gas discharge arrester) and
secondary (MOVs) protection against induced transients generated from lightning strikes. The primary
protection device is a three electrode gas filled surge protector tube. These devices simultaneously
ground both sides of a pair when a surge appears on either line of the pair. The tube then restores when
the surge dissipates. The secondary protection feature grounds any high voltage peak (spike) which
might be passed by the primary protector. A high power inductor placed between the primary and
secondary protectors exhibits a high impedance for most lightning induced voltage transients. This high
impedance insures that the primary protector will operate first and the secondary protector will not be
exposed to the full surge. The LPU is designed to be installed in series between the PV array and a
Specialty Concepts designed PV system control electronics. Specialty Concepts designed electronics
have additional lightning protection features in the form of MOVs that compliment the action of the LPU.
Terminals are provided for connection to "ARRAY IN" and "ARRAY OUT" plus and minus for each
sub-array for each sub-array. Each sub-array channel is rated for 50 amps and is suitable for use in DC
systems up to 48 volts DC nominal. Provisions are made for earth ground for each channel and for a
chassis ground. The standard LPU is provided with a steel, wall mount, gasketed enclosure.
Note: The standard LPU is designed for negative ground systems. DO NOT wire the array with a common
positive ground connection to the battery as this will reduce the effectiveness of the LPU.
FEATURES
SYSTEM LIGHTNING PROTECTION
•
50 amp, up to 48 volt nominal capacity per
channel
•
Two stage protection
- High capacity gas discharge tube
- Fast response MOV
DESIGN FEATURES
•
4 gauge terminal block connection
•
Earth and chassis ground connections
•
Higher capacity available by paralleling
channels
•
Negative ground
•
Positive ground available (optional)
•
Wall mount indoor enclosure
•
Outdoor enclosure available (optional)