Service Clearance
In addition to national and local code requirements, 32 inches of service clearance is needed at the front of the SPD.
Equipment Performance
To obtain the maximum system performance, the unit must be located as close to the circuit to be protected as possi-
ble, minimizing the interconnecting wire length. For every foot of wire length, approximately one (1) nanosecond of
turn-on/turn-off time will be added, and approximately 175 volts (6kV/3kA, 8/20 microseconds) will b e added to the
clamp voltage.
For optimum transient surge protection, staged surge suppression should be implemented at the service entrance and
all other electrical connections to the building (telephone, CATV, etc.). It should also be implemented at recognized
surge generating loads within the building (arc welding rigs, large motors, switched capacitors, etc.). Additionally, it
should be implemented for sensitive electronic loads (computer equipment, facsimile machines, copy machines, solid
state motor drives, variable frequency drives, etc.). For interconnected electronic loads (via data cabling), surge pro-
tection devices should also be utilized to protect the devices on either end of the interconnecting data cables.
APC manufactures a complete line of surge protection devices for both alternating current (AC) and direct current
(DC) applications. Contact an authorized APC reseller, or order directly from APC at www.apc.com.
Product Orientation
To decode the Model Number and determine the unit’s configuration, locate the printed nameplate on the inside of the
unit door. Note: The Serial Number, Date of Manufacture, and UL 1449 Suppression Voltage Rating (SVR) are also
on the unit identification nameplate. The Model Number can be decoded as follows:
30LGHQWLILHVD6XUJH$UUHVW3DQHO0RXQWSURGXFW7KHIROORZLQJOHWWHULQGLFDWHVWKHYROWDJHDQGZLULQJFRQ
ILJXUDWLRQRIWKHGHYLFH
)ROORZLQJWKLVOHWWHULVWKHQXPEHU7KLVQXPEHULGHQWLILHVWKHVXUJHFXUUHQWUDWLQJVWREHN$SHUSKDVH
)ROORZLQJWKHQXPEHULVWKHOHWWHU;7KLVLQGLFDWHVWKDWWKHXQLWLVQRQPRGXODU
)ROORZLQJWKHOHWWHUGHVLJQDWLRQLVRSWLRQDOHTXLSPHQWVKRZQDV' 'LVFRQQHFW6 6XUJH&RXQWHU
2SWLRQVDUHGHWDLOHGODWHULQWKLVPDQXDO
System Grounding
An equipment grounding conductor must be used on all electrical circuits connected to the SPD. This requirement is
primarily for safety, although SPD performance is enhanced by proper grounding. Proper operation of any surge sup-
pression system or device depends on a proper grounding system. Incorrect grounding practices will reduce the effec-
tiveness or interfere with SPD system operation and performance, as well as endanger personnel and equipment. For
the best performance, use a single point ground system where the service entrance grounding electrode system is con-
nected to and bonded to all other available electrodes, building steel, metal water pipes, driven rods, etc. For sensitive
electronics and computer systems, it is recommended that the ground impedance measurement be 25 ohms or less.
When a metallic raceway is used as an additional grounding conductor, an insulated grounding conductor should be
run inside the raceway. Adequate electrical continuity must be maintained at all raceway connections. Do not use iso-
lating bushings to interrupt a metallic raceway run. A separate isolated ground for the SPD is NOT recommended.
**On 4-Wire Power Systems, neutral to ground bonding should be
installed per the NEC. Failure to do so could cause equipment damage.**
ELECTRICAL CONNECTIONS
Overcurrent Protection
The Surge Protection Device (SPD) draws very little current under normal conditions and will only conduct for a
brief duration upon encountering a transient surge voltage. APC SPDs contain UL Listed internal fusing to protect
against abnormal voltage conditions. Note: Fuses are not replaceable.
Voltage Rating
Prior to mounting the SPD, verify that the unit has the correct voltage rating by checking the nameplate voltage or
model number. The service type should match the intended power source. See Table 1 for the voltage rating and ser-
vice type of the SPD.
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