Quantum Q280 User Manual

4.3
Grounding, Electrostatic Discharges, and EMI
The 5 Vdc and 12 Vdc returns are connected to the base casting. The
metal shock mount brackets are electrically isolated, and the face-
plate is plastic. Therefore, mounting the drives by the mounting
holes in the shock mount brackets does not directly connect the base
casting to cabinet ground. If desired, an installer can run a ground
wire (a heavy braid is recommended to ensure low impedance to high
frequencies) from cabinet ground to the male tab-type grounding lug
fastened to the base casting. The male lug is AMP Faston PIN 61761-2.
One suitable mating part is a push-on receptacle, AMP PIN 62187-1,
which accomodates 18 AWG wire. The mating part used should be chosen
to accept the grounding braid.
Such a ground connection is desirable if:
o Electrostatic discharges occur (for example, by personnel
touching the drive after walking over a carpet). These may
cause soft (random, non-repeating) errors, but discharges
over 20 kilovolts may cause permanent damage.
o Electromagnetic Interference (EMI) is present. Excessive
EMI may also cause soft errors.
EMI may be due to nearby radio or TV stations, chopper-type power
supplies (especially those operating from the same 5 volts or 12 volts
as the Q250/Q280 drive), heavy electrical machinery such as elevators
and motors, even lamp dimmers. The drive is rated to operate in a
strong field: up to 4 volts/meter over a range of 20 Hz to 20 MHz.
If EMI is suspected and grounding doesn't help, use some common sense
analysis: see if the problems occur only when the suspected source is
operating; try different, dedicated sources of 5 volts and 12 volts.
Surge suppressors in the ac lines to other equipment may help. If the
problem persists, contact Quantum's Technical Support Group.
4-10

Quantum Q280 Specifications

General

Brand	Quantum
Model	Q280
Category	Storage
Language	English