INTRODUCTION
Thank you for choosing an APT Surge Protective
Device (SPD). This is a high quality, high energy
surge suppressor designed to protect sensitive
equipment from damaging transient overvoltages.
Proper installation is important to maximize
performance. Please follow steps outlined herein.
This entire Operation and Maintenance Manual
should be read prior to beginning installation.
These instructions are not intended to replace
national or local codes. Follow all applicable
electrical codes to ensure compliance. Installation
of this SPD should only be performed by qualified
electrical personnel.
APT SPDs are extensively tested in accordance
with industry standards such as ANSI/IEEE
C62.41.1, C62.41.2, C62.45, C62.62, C62.72, UL
1449, UL 1283, IEC 61643, etc.
This SPD is a single-port parallel-connected device
intended for service entrance, panelboard or
downstream installation for IEEE Category C, B or
A applications.
Major Industry Nomenclature Changes
Effective 2008-2009
Be aware that UL 1449 Third Edition and 2008
NEC
Article 285 generated substantial changes.
®
• The term TVSS changed to SPD.
• Types 1, 2, 3 & 4 SPDs are created.
• UL 1449 clamping voltage performance testing
changed from 500A to 3,000A.
• UL 1449 added new I nominal testing (I
consists of more rigorous duty-cycle testing.
• This SPD complies with the latest regulatory
actions and is UL Listed as such.
• For further information, please review latest
editions of NEC
Article 285, UL 1449 or
®
contact APT Tech Support at (800) 237-4567.
Figure 1
NEC
SPD Types: Types 1, 2, 3, & 4
Based on Location within electrical distribution system
(also coincides with ANSI/IEEE C62.41.2 - 2002 Categories C, B & A)
2
), which
n
ARTICLE 285
®
& UL 1449-3
GENERAL INFORMATION
This is a Type 1 SPD. Type 1 SPDs include internal
overcurrent protection and have been evaluated
by UL to more stringent requirements. Type 1
SPDs are suitable for installation on the line side
or load side of the service disconnect overcurrent
device. (cUL models are Type 2 due to different
cUL criteria.)
This device features internal overcurrent and
overtemperature protection that will disconnect
effected surge suppression components at the
end of their useful life, but will maintain power
to the load – now unprotected. If this situation
is undesirable for the application, follow these
instructions for servicing or replacing the device.
Service of this unit consists of replacing it or factory
service. There are no user-serviceable parts
inside the replaceable module. Do not attempt to
disassemble the unit as it stores charge.
Simplified Explanation of Operation
SPDs sense overvoltage and create a momentary
short circuit to redirect harmful surge energy to
earth ground. Then they reset automatically
and wait for the next surge. This is similar to the
pressure relief valve on a water heater: pressure
goes up, valve opens to relieve pressure and then
resets. In an electrical system, an SPD senses
overvoltage, shorts temporarily sending energy
to ground and then resets. SPDs are capable of
repeating this function thousands of times.
Parallel Connection
This is a Parallel connected SPD – not series
connected. As outlined above, an SPD 'drains
off' excessive voltage from an electrical system.
Because of parallel connection, installation of the
SPD anywhere near the equipment to be protected
is satisfactory. This effect is similar to flushing any
toilet in a house; pressure in the shower goes down.
In an electrical system, a parallel connected SPD
will remove excessive voltage off the entire system
(assuming reasonable proximity).
Tip: It is critically important that wiring leads be configured
as short and straight as possible. Avoid long leads. Avoid
sharp bends. Route SPD conductors in the same conduit.
Leads do not have to be sized for the entire load – this
SPD is parallel connected, not series connected. As a
generalization, 8 AWG works fine on this product.
Precautionary Statement Regarding SPDs on
Ungrounded Systems
Caution: Ungrounded systems are inherently
unstable and can produce excessively high line-
to-ground voltages during certain fault conditions.
During these fault conditions, any electrical
equipment including an SPD, may be subjected
to voltages which exceed their designed ratings.
This information is being provided to the user
so that an informed decision can be made
before installing any electrical equipment on an
ungrounded power system.