4
2.2 Power Connections
Make sure that all local and national electrical standards are met when the installing the unit. Contact your local authorities to
determine which codes apply.
2.2.1 Power Requirements
Power
The HMI can be powered by DC power only. The specified voltage range is +22 to 25
Volts DC. This insures compatibility with most controller DC systems.
The power conditioning circuitry inside the unit is accomplished by a switching power
supply. The peak starting current can be as high as 700mA.
Fusing
Requirements
It is recommended that all input power lines be protected from incorrect wiring or
product failure by a 2 Amp fuse or a breaker.
If the display does not come on within 2 seconds of power up, remove power. An
internal fuse prevents damage if the polarity of the DC power is incorrect. Check wiring
to insure proper connections and try to power up again.
Warning!
High Voltage
Connecting high voltages or AC power mains to the DC input makes the unit unusable
and may create a hazard to personnel. Such a failure 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.
Supply Voltage
Condition
Do not power the HMI and inductive DC loads, or input circuitry to the controller, with
the same power supply.
Note:
The 24 VDC output from some controllers may not have enough current to power
the HMI.
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.
Electrical
Environment
The MMI Series has been tested to conform to European CE requirements. This means
that the circuitry is designed to resist the effects of electrical noise. This does not
guarantee noise immunity in severe cases. Proper wire routing and grounding insures
proper operation. The MMI Series is also UL certified.
Warning!
Emergency
Stop
A Hard-wired EMERGENCY STOP should be fitted in any system using an HMI to
comply with ICS Safety Recommendations.
Summary of Contents for MMI-1500
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