Application Note Use of Palm Switches with QuadTech Hipot Testers Operator safety is an important aspect to consider when dealing with high voltage devices and instruments such as hipot testers. To improve operator safety there are a number of features manufacturers have incorporated into todays high voltage test equipment. For example todays digital hipot testers produce less output current than the typical analog 500VA hipot tester used in the past. Todays instruments also incorporate interlocks, ground fault interruption (GFI) and remote I/O. Regardless of the high voltage device or instrument, there is no substitute for proper training of employees when it comes to safety. One safety feature that will be discussed in this application note is the use of palm switches that can reduce the possibility of an operator coming in contact with high voltage. The basic operation of a palm switch requires the operator to use both hands to initiate a test and if one or both of the hands are removed while testing, the test is immediately stopped. The switches are usually placed directly in front of the operator spaced shoulders width apart. Spacing the switches prevents an operator from trying to press both buttons down with one hand or object. Figure 1 illustrates a set of Auxiblock 30mm Palm Switches manufactured by Baco Controls Inc of Cazenovia NY, and disributed by McMaster Carr. A Parts List is included for reference. Figures 3 through 5 illustrate this set of palm switches connected to three of QuadTech s Hipot Testers. Figure 1: Baco Controls Palm Switches
Parts and Wiring Parts List: Auxiblock 30mm Series Palm Switches Quantity Part Number Description Price each (USD) 2 T12AD01 Red 40mm Mushroom Head Spring Return Button $15.57 2 233E Clip with Locking Lever for Contact Modules $ 0.75 2 23E01 Contact Module NO Single Contact $ 4.32 2 23E10 Contact Module NC Single Contact $ 4.32 2 BPA301 Nema 4 High Impact ABS Enclosure $ 27.15 Additional Items 2 Heyco 3213 Cord Connectors 20 (Feet) Multiconductor Cable (4 conductor 22/24 guage) Manufactured by: Baco Controls Inc 67 Albany Street Cazenovia, NY 13035 315-655-8372 Distributed by: McMaster Carr STOP COMMON GROUND Remote Terminal Strip Figure 2: Wiring Diagram of Auxiblock 30mm Series Palm Switches
Sentry Series Connection The Sentry Series of Hipot Testers are capable of generating an output voltage as high as 6000VDC (5000VAC) to the device under test. To protect the operator from potentially hazardous levels of energy, use the Palm Switch configuration illustrated in Figure 3. There is no High Voltage applied to the Output Terminals and DUT until BOTH switches are pressed simultaneously. The operator cannot touch the DUT or test leads if both hands are on the palm switches. SAFE, quick and effective. Palm Switches Placed Shoulder Width Apart In front of Hipot Tester CE FAN (50 C AUTO ON/OFF) VOLTAGE SELECTOR 100V~ 120V~ 220V~ 240V~ R E M O T E RESET COM INTER LOCK PASS FAIL Cont. Check Option 100V/120V/220V/240V~ 50/60Hz 300W MAX QuadTech Serial No. 1 CAL Fuse Rating T3.15A 250V REMOTE Terminal Strip Rear Panel Sentry Series Hipot Tester Red Wire/clip to RESET Black Wire/clip to Gray Wire/clip to COM Figure 3: Connection of Palm Switches to a Sentry Series Hipot Tester
Guardian 6000 Series Connection Figure 4 illustrates the Auxiblock Palm Switches connected to QuadTech s Guardian 6000 Electrical Safety Analyzer. Connection is via the REMOTE terminal strip on the rear panel of the Guardian 6000. The Guardian 6000 can perform five tests (AC Hipot, DC Hipot, Insulation Resistance, Leakage Current and Ground Bond) with a single test connection. This can effectively reduce test time and increase product throughput. With the use of the palm switch setup, the operator needs only to connect the DUT, press both palm switches, then disconnect the DUT. Test results can be output to a computer via the GPIB terminal. A fast and cost effective mode of testing but most importantly a SAFE test setup. Palm Switches Placed Shoulder Width Apart In front of Hipot Tester Optional Rear Panel Output SENSE GPIB SCAN RS232 WARNING CAUTION PASS RESET FAIL FAN 50 o C AUTO ON/OFF QUADTECH Serial No. DRIVE RESET HV Output PASS 100V~ COM 220V~ HIGH VOLTAGE MAX: 5KV AC 6KV DC CH1 CH2 120V~ FAIL INTER LOCK 240V~ CH3 CH4 CH5 CH6 CH7 CH8 FUSE RATING 100/120V T6.3A 250V 220/240V T3.15A 250V REMOTE Terminal Strip Rear Panel Guardian 6000 Electrical Safety Analyzer Red Wire/clip to RESET Black Wire/clip to Gray Wire/clip to COM Figure 4: Connection of Palm Switches to Guardian 6000 Electrical Safety Analyzer
Guardian 2500 Series Connection Figure 5 illustrates the connection of the Auxiblock Palm Switches to the Guardian 25xx Series Hipot Tester. Connection is made to the REMOTE I/O on the rear panel via a female D-series 9 PIN connector. Remove the spade clips from the end of the palm switch wires. Open casing of female connector and from the back side, solder the double red wire to pin 2 (STOP). Solder the black wire to pin 3 (). Solder the gray wire to pin 5 (COMMON). Replace casing of female connector and plug the new assembly into the REMOTE I/O terminal on the rear panel of the Guardian 25xx instrument. Palm Switches Placed Shoulder Width Apart In front of Hipot Tester REAR PANEL GUARDIAN 25xx Series HIPOT ER CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH SAME TYPE AND RATING OF FUSE NO USER SERVICIABLE PARTS INSIDE. TO PREVENT ELECTRICAL SHOCK DO NOT OPEN COVERS. REFER TO QUALIFIED PERSON RS-232 MADE IN USA FUSE 250V 100-240V T5.0A 5x20mm CAUTION HIGH VOLTAGE GC RETURN HV OUT AUXILLIARY 100-240V 50-60Hz 300 WATTS MAX REMOTE I/O 5 STOP 5 Black wire to Pin 3 Red wire to STOP Pin 2 Gray wire to COMMON Pin 5 9 6 1 1 9 6 PASS FAIL REMOTE I/O ENLARGED FOR DETAIL REMOVE 3 SPADE LUGS SOLDER WIRES TO BACK SIDE OF FEMALE CONNECTOR. REPLACE CASING OF CONNECTOR FEMALE 9-pin D-Series Connector Plug into REMOTE I/O on rear 25xx MALE 9-pin D-Series REMOTE I/O Connector Figure 5: Connection of Palm Switches to Guardian 25xx Series Hipot Tester
Conclusion As you can see, it is easy to adapt the palm switch configuration to the Hipot Tester being used. Give QuadTech a call and let our Applications Engineers discuss your Electrical Safety Testing instrumentation and accessory needs. If you have an application specific test and measurement need, and can t commercially find an instrument that does the job, call us. We can modify our instrumentation to fit your testing needs and we ll have a solution back to you in 48-hours or less. We would be happy to design a test setup that s safe, accurate and fast to meet your production and laboratory requirements. The information presented here is subject to change and is intended for general information only QuadTech, Incorporated Telephone: 1-800-253-1230, Website: www.quadtech.com Printed in U.S.A. PN 035080 May, 2000