KEP MMI-7 Series Installation Instruction page 3

Connecting high voltages or AC power mains to the DC input makes the unit
Warning!
unusable and may create a hazard to personnel. Such a failure could result in
High Voltage
serious personal injury, loss of life and or equipment damage.
DC voltage sources should provide proper isolation from main AC power
and similar hazards.
Supply Do not power the MMI and inductive DC loads, or input circuitry to the
Voltage controller, with the same power supply.
Condition Note: The 24 VDC output from some controllers may not have enough
current to power the MMI.
Wire Routing Wire lengths should be minimized.
Wires should be run in pairs with a neutral or common paired with a hot or
signal line.
Always use shielded cable to prevent unwanted electrical interference.
If wiring is to be exposed to lightning or surges, use appropriate surge
suppression devices.
Keep AC, high energy, and rapidly switching DC wiring separate from
signal wires by at least 8 inches. If signal wires must cross AC power, cross
at right angles.
Equip ungrounded DC supplies with a resistor and capacitor in parallel to
earth ground. This provides a path for static and high frequency dissipation.
Typical values to use are 1MOhm and 4700pF.
The MMI Series has been tested to conform to European CE requirements.
Electrical
The circuitry is designed to resist the effects of electrical noise. This does not
Environment
guarantee noise immunity in severe cases. Proper wire routing and
grounding insures proper operation. The MMI Series is also UL certified.
A Hard-wired EMERGENCY STOP should be fitted in any system using an
Warning!
MMI to comply with ICS Safety Recommendations.
Emergency
Stop
Chassis ground must be used. DC ground is not directly coupled to Earth
Grounding
ground internally. It is preferable not to ground DC negative return to
Requirements
chassis ground. Poor site earths can introduce noise into a system. If
necessary, an earth connection should be made from the power supply
return point to the central star earth point.
Ground conductors should be as short and as large in diameter as possible.
The conductors must always be large enough to carry the maximum short
circuit current of the path being considered. Ground conductors should be
connected to a tree from a central star earth ground point. This ensures that
no ground conductor carries current from any other branch.
To make an MMI comply with EMC directives, and to reduce susceptibility
CE
to electrical interference, a separate #14 AWG ground wire should be taken
Requirements
to the chassis ground terminal of the power connector. This ground
connection should be run directly to the central star earth connection point
(as recommended in most Installation Instructions).
Use a ferrite core on the power wiring to reduce radiated emissions from the
DC power lines. It is recommended to use a 140Ohm@100MHz ferrite core
with the DC power lines looped through the core once. Position the ferrite
core less than 1" away from the DC power connection points on the back of
the MMI.
140 Ohm @ 100MHz ferrite
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