Valleylab Force FX-8C, Service Manual

Page: 107 / 218

Periodic Safety Check
Setup, T
ests, and Adjustments
Force FX-8C Service Manual 5-23
Checking High Frequency Leakage Current
Check the high frequency leakage current and ground resistance before
returning the Force FX-8C generator to clinical use. Check the leakage
current
• After calibrating the generator
• Every six months.
Equipment required:
• 200 ohm, 250 watt, noninductive resistor
• Current transformer
• True RMS voltmeter (Fluke 8920 or equivalent)
• Bipolar and monopolar footswitches
• Leakage table - per IEC 601-2-2, Figure 104.
Checking Monopolar High Frequency Leakage Current
1. Connect the 200 ohm load from the active accessory through the
current transformer to the equipotential ground lug on the rear of the
generator.
2. Connect the current transformer to a true RMS voltmeter.
3. Connect a monopolar footswitch to the Monopolar 1 Footswitch
receptacle on the rear panel.
4. Activate the footswitch in each Monopolar mode at the maximum
control setting. Record the leakage current. If using the leakage table,
leakage current should not exceed 150 mA for any mode.
5. If the high frequency leakage exceeds 150 mA, call the Valleylab
Service Center for further instructions.
Checking Bipolar High Frequency Leakage Current
1. Remove the monopolar accessories, and connect the 200 ohm load
from one side of the bipolar output through the current transformer to
the equipotential ground lug on the rear of the generator.
2. Connect the current transformer to the true RMS voltmeter.
3. Connect a bipolar footswitch to the Bipolar Footswitch receptacle on
the rear panel.
4. Activate the footswitch in each mode at maximum control setting.
Record the leakage current. It should not exceed 60 mA for any mode
using either the leakage table or short lead configuration.
5. If the high frequency leakage exceeds 60 mA, call the Valleylab Service
Center for further instructions.