- First
is the selection of the proper SPD for the application,
- Second
is the placement of the SPD, and
- Third
are the procedures required for a safe installation of the SPD.
Installers
should know the operating voltages of the circuits they work on, so
they can match those with SPD ratings applicable for each specific
installation. Be sure to check all line voltages, never attempt to
install an SPD on a circuit with voltages exceeding the maximum
continuous operating voltage (MCOV) of the unit.
The SPD should be rated for the
symmetrical fault current available. If an SPD with a lower
symmetrical fault current rating than required is installed, then the
SPD enclosure may be compromised, emitting debris and hot gases during
a catastrophic failure.
Ensure the unit selected will easily
mount in the area provided. Mount hardwired SPD's as close as possible
to the panel to be protected. Hardwired SPD’s are most effective
when the wires are as short and straight as possible. Avoiding 90º
bends and using only smooth curves is highly recommended. If the
hardwired SPD has a metal enclosure, use a metal conduit to connect
the SPD to the protected panel.
The selected SPD must be capable of
existing in the operating environment where it is installed.
It may be necessary to add additional
access points for remote monitoring or other purposes. It is advisable
that the manufacturer perform all such modifications.
Ideally, securing all electrical power
during the installation of the SPD is the safest method. However, more
often than not, securing all electrical power is not possible. In
these cases, some basic safety steps are
required while working near energized gear:
- Take special care when mating jaw
blades during a meter-base SPD installation. The installer must be
sure to observe the position of the jaw blades while inserting the
meter into the meter-base SPD. A missed jaw blade may make
electrical contact but will not provide full load current
capability.
- Follow the manufacturers recommended
practices for greasing of the jaw blades. Excessive amounts (or
the incorrect type) of grease may cause accelerated corrosion of
the jaw blades.
- A screw-type-locking ring is
recommended to secure the electric meter to the installed
meter-base SPD. A screw-type-locking ring will provide a more
secure connection between the meter and the meter-base SPD. The
opening of the locking ring should be at the bottom of the meter
to allow for proper moisture draining.
- If possible, use a designated
circuit breaker in the electrical panel to connect the hardwired
SPD. Some hardwired SPD’s have an integral circuit breaker or
other over-current protective device and may be directly installed
on the electrical panel. Connecting hardwired SPD's to circuit
breakers already in use may be done if permitted by local codes.
- Finally, ensure that all connections
are correct and secure before energizing.
Please call the
factory if further assistance is required.
Remember, there are no
short cuts when safety is concerned.
