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Chapter 3 – Installation
3-25
Voltage Available Current
a
AHIP5+ AHIP6+
+12 VDC 4.88A 4.88A
-12 VDC 0.46A 0.76A
-5 VDC 0.50A 0.50A
a
Total expansion power not to exceed 100 watts
b
Combined 3.3V and 5V expansion is 10.6A
It is a good idea to use isolation transformers on the system’s incoming AC power line. An
isolation transformer is especially desirable in cases where heavy equipment is likely to in-
troduce noise onto the AC line. The isolation transformer can also serve as a step-down
transformer to reduce incoming line voltage to a desired level. The transformer should have
a sufficient power rating (units of volt-amperes) to supply the load adequately.
Proper grounding is essential to all safe electrical installations. Refer to the relevant Fed-
eral, State, Provincial, and local electric codes which provide data such as the size and
types of conductors, color codes and connections necessary for safe grounding of electri-
cal components. The code specifies that a grounding path must be permanent (no solder),
continuous, and able to safely conduct the ground-fault current in the system with mini-
mal impedance (minimum wire required is 18 Awg, 1 mm).
Observe the following practices:
•
Separate ground wires (P.E. or Protective Earth) from power wires at the point of
entry to the enclosure. To minimize the ground wire length within the enclosure, lo-
cate the ground reference point near the point of entry for the plant power supply.
•
All electrical racks or chassis and machine elements should be Earth Grounded in in-
stallations where high levels of electrical noise are expected. Ground the chassis
with a ground rod or attach to a nearby Earth structure such as a steel support beam.
Each different apparatus should be connected to a single Earth Ground point in a
“star” configuration with low impedance cable. Scrape away paint and other non-
conductive material from the area where a chassis makes contact with the enclosure.
In addition to the ground connection made through the mounting bolt or stud, use a
one-inch metal braid or size #8 AWG wire to connect between each chassis and the
enclosure at the mounting bolt or stud.
Excessive Heat
The system withstands operating temperatures from 0º to 50º C (32º to 122º F). To keep
the temperature in the specified range, the air at the base of the system must not exceed
50°C. Allocate proper spacing between internal components installed in the enclosure.
When the air temperature is higher than 50ºC in the enclosure, use a fan or air condi-
tioner.
Electrical Noise
Electrical noise is seldom responsible for damaging components, unless extremely high
energy or high voltage levels are present. However, noise can cause temporary malfunc-
tions that can result in hazardous machine operation in certain applications. Noise may
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