Advanced Protection HPS - Manual (Page 4)

4
PRE-INSTALLATION & INSTALLATION PLANNING
Operating Environment
The standard unit uses a Type 1/12/3R/4 enclosure. Non-
metallic polycarbonate 4X, stainless steel and Type 1 flush
mount or pull box enclosures are available as options.
Before installing, ensure that your enclosure type and
application are appropriate per NEMA 250 with regard
to moisture, dirt, excessive dust, flammable materials or
atmospheres, corrosive vapors, etc. Please consult factory
if enclosure needs to be changed.
This SPD is designed in an ambient temperature range
of -40°C (-40°F) to +60°C (+140°F) with a relative
humidity of 0% to 95% (non-condensing). Excessive
temperature may inadvertently operate internal thermal
overtemperature protectors.
Load Side Installation
HP and HPS SPDs are tested and qualified as Type 2
SPDs per UL 1449 Third Edition and 2008 NEC ® . These
SPDs are intended for load side installation of the service
overcurrent device per 2008 NEC ® 285.
When connected on load side of main disconnect, we
suggest connecting via a 60A circuit breaker. The circuit
breaker is the intended disconnect switch and provides
short circuit protection to the connecting conductors. The
HP and HPS families have internal overload protection
elements within the product. A breaker or disconnect is
not required for the SPD’s overcurrent protection. HP
and HPS SPDs have demonstrated 200kA Short Circuit
Current Ratings (SCCR). Confer to label on unit.
Audible Noise
SPD background noise is negligible or non-existent, and
does not restrict the location of installation.
Mounting, Dimensions, and Weight
The HP and HPS series include enclosures and are
intended for wall mounting. (The XTE/HP and XTE/HPS
are component SPDs intended for installation within other
electrical gear already having enclosures.)
This SPD is designed to be wall mounted. The standard
enclosure is: 12” x 12” x 6” (L/W/D), and the weight is 25
lbs. The XTE Series is designed for internal mounting in the
electrical distribution equipment. Standard backplane size
is: 10.75” x 10.88” x 4.5”, and the weight is 61 lbs. (Verify &
check numbers). See Table 2 below.
Table 2: DIMENSIONS & WEIGHTS
HP H/W/D (in. / mm.) Weight
Standard 12"x12"x6" (305x305x152) 25 lbs (11.3 kg)
HPS H/W/D (in. / mm.) Weight
Standard 12"x12"x6" (305x305x152) 25 lbs (11.3 kg)
Lead Lengths & Maximizing SPD Performance
SPD’s must be located as close to the circuit as possible
to minimize parasitic losses. Surges are high current, high
frequency events that cause substantial voltage drops
across conductors. This hurts SPD performance. Use the
shortest & straightest possible leads. Pre-Plan installations
and ensure that nearest breaker positions are used. If new
construction, adjust breaker locations as appropriate.
Tip: Voltage drops for normal 120V or 277V lines might be 2-3V
per hundred feet. In surge applications, voltage drops might
be 100-150V per foot. These voltage drops add to clamping
voltage, thus hurting performance. Make every effort to keep
leads short and straight. As distribution gear becomes larger,
shorter leads are more difficult to accomplish. When longer
leads are unavoidable, gently twist leads together (one to two
twists per foot), or tie-wrap leads together.
Tip: surges create magnetic fields per the ‘right-hand rule’.
When current goes in direction of thumb, magnetic field is
in direction of curl of fingers. As surge current goes to SPD,
fields are created in one direction. When the SPD sends those
currents to neutral and/or ground, current goes in the opposite
direction. If ‘coming & going’ are on the same axis, the magnetic
fields can be cancelled, thus avoiding performance decrease.
Gentle twists, bundling & tie-wraps accomplish this.
Shortest Leads Possible
▪
Leads must be as short and straight as possible -
See NEC ® Art. 285.12
▪
Pretend wire is $1000 per foot coming out of your pocket.
▪
No long leads
▪
No sharp bends
▪
No wire nuts
▪
How short is short enough? As short as you can make it.
▪
How long is too long? If anyone else can make it shorter.
Overcurrent Protection
SPDs draw very little current under normal conditions and
conduct for a brief duration upon encountering a transient
surge current. This SPD contain internal overcurrent and
overtemperature protection to protect against abnormal
voltage conditions.
Supplemental overcurrent protection is not required to protect
this SPD. However, connecting conductors require protection
in Type 2 or 4 applications. Follow applicable codes.
Voltage Rating
Before installing SPD, verify that it has the same voltage
rating as the power distribution system. Compare the SPD’s
nameplate voltage or model number and ensure that SPD
configuration matches the intended power source. See Table 1.
The specifier or the user of the device should be familiar with the
configuration and arrangement of the power distribution system
in which any SPD is to be installed. The system configuration
of any power distribution system is based strictly on how the
secondary windings of the transformer supplying the service
entrance main or load are configured. This includes whether
or not the transformer windings are referenced to earth via a
grounding conductor. The system configuration is not based on
how any specific load or equipment is connected to a particular
power distribution system.
480V System Example: SPDs should be installed per the
electrical system, not per a load or motor’s wiring connection.
For example, a 480V three phase motor might appear to be
connected as a 480V Delta. In actuality, the serving distribution
system might be a 480Y/277V grounded Wye, with or without
a neutral pulled to the motor or MCC. The system is still a
480Y/277V Wye, even though the load is connected as a
Delta. A grounded Wye has a defined reference to ground
(i.e., neutral is bonded to ground). Some Delta systems are
ungrounded, which have no reference to ground and are known
to become unstable in certain situations. Such instability can
cause line to ground voltage fluctuations that may prematurely
fail SPDs. For this reason, the NEC ® Article 285 has placed
SPD restrictions on ungrounded systems. As generalizations,