Microcom 334M Operator's Manual page 59

Getting Started
operation of the printer and media. The operator can become caught on cabling and drop
heavy media damaging the kiosk, printer, or hurting themselves.
• Service Loops - There should be enough slack in the cabling to not put pressure on the
cable connectors or the circuit boards. Enough slack is needed to disconnect the printer (or
their kiosk components) for servicing. Allow for movement needed to access the cable locks
or slide the printer out.
• Avoid electrical noise sources: fluorescent lighting and ballast, power supplies, fans, AC
power lines, CRT monitors, etc.
• Avoid twisting power and communication cables together. This can cause electrical noise
on the communication port or raise emissions levels.
3.8.7 Power Supply Requirements
Thermal printers have special power requirements to operate correctly and safely within
compliance regulation guidelines. To achieve optimum performance, an approved power
supply should be used. Power supplies sold by Microcom Corporation have gone through
rigorous testing to ensure the proper function of the printer. If a non-Microcom supplied
power supply is used with the printer, it must comply with the requirements of that printer.
The same ground MUST be used for the printer, printer power supply, and any device (PC,
USB hub, etc.) connected to the printer communication ports, and the same AC power
circuit should be used whenever possible for these devices. If the printer does not have an
integrated power switch, it is recommended that the power supply have one on the ac input
side to the power supply. Plugging and unplugging the 24 volt supply into the back of the
printer hot can cause damage to the printer. Using an insufficient power supply can cause
damage to the printer. Thermal printers require high over current peaks of power that must
be handled by the power supply. When Short Circuit Protection or Over Current Protection
is activated, the power supply should shutdown automatically. Once the abnormal condition
resulting in the failure is removed, the power supply should restart accordingly. If over
Voltage Protection is activated, the power supply will shut down. The power supply should
be fully protected against short circuits and automatically recover gracefully.
It is highly recommended that Microcom provide the power supply in order to prevent
damage to the printer or cause the printer not to function properly.
3.8.8 Electrostatic Discharges and Ground Connections
The printer should have a dedicated earth ground connection. Preventing ESD and earth
currents from affecting the printers operation requires proper connection to the printer
chassis via a 12 AWG wire to earth ground. The ground wire should be connected to the
printer chassis using a closed loop connector. Measure the resistance with an ohm meter to
ensure proper grounding.
The same ground MUST be used for the printer, printer power supply, and any device (PC,
USB hub, etc.) connected to the printer USB or serial ports. The same AC power circuit
ground location should be used whenever possible for these devices.
If the printer is in a low humidity environment, the use of anti static brushes or tinsel may be
required.
3-41 334M Operator's Manual - 880060-0110
Chapter 3