Maple Systems HMC7000 Series - Manual (Page 14)

HMC7000 Series Installation Guide
Phone: 425/745-3229 • Fax: 425/745-3429 • Email: [email protected] • www.maplesystems.com
1010-1042 Page 12 of 22 Rev. 02, 09/25/2013
Power Supply Selection
The power supply used to power the HMC should provide an output of +24 VDC ±20% measured at the HMC power
terminal block. A 24VDC regulated power supply dedicated to the HMC is recommended. Use a power supply with
adequate current rating based upon your particular model (visit the Support Center Specifications page on our website).
Do not use the power supply used to provide power to the HMC to power switching relays, solenoids, or other active
devices.
Use appropriate surge suppression devices in areas subjected to lightning or power surges. Keep AC lines, high
energy equipment cables and rapidly switching DC wiring separate from the HMC power and signal wires.
Connecting high voltages or AC power mains to the DC input will make unit unusable and may create an electrical shock
hazard to personnel. Such a failure or shock could result in serious personal injury, loss of life and/or equipment damage.
DC voltage sources should provide proper isolation from main AC power and similar hazards.
A power line filter installed at the AC input to the HMC power supply is highly recommended as a safeguard against
conducted RF noise, which is often present on factory power lines. The wires connecting the output of the power line
filter to the power supply should be kept as short as possible to minimize any additional noise pickup. The case of the
power line filter should be connected to a quiet earth ground. The power line filter should have a current rating of at least
3 Amps with common mode and differential mode attenuation. In applications that may have high frequency noise
present, we also recommend using a resistor (~1 MΩ) and capacitor (~4700 pF) in parallel to clean earth ground on the
DC output of the power supply.
Figure 3: Power Line Filter Connection
Cable Routing and Noise Immunity
Follow these guidelines when routing cables to the HMC:

Always route the HMC communication cable and the power cable away from any AC voltage or rapidly
switching DC control lines.

Never bundle the HMC cables together with 120VAC power wires or with relay wiring.

Try to keep at least 8 inches (20 cm) of separation between the HMC cables and other power wiring. If
voltages greater than 120VAC are used in the system, greater separation is required.

If the HMC cables must come near AC wiring, make sure they cross at 90 degrees.

Run AC power wires in a separate grounded conduit to reduce electrical noise interference.

Keep the cable lengths for the HMC as short as possible. Do not coil excess cable and place it next to AC
powered equipment.

Cover any equipment used in the enclosure that operates at high frequency or high current levels with a
grounded metal shield.