PRINTABLE VERSION
Technical Bulletin # 216
PROCEDURE FOR REMOVING DOUBLE PACK MODULE
Tools Required:
- 9/16" Wrench
- 11/16" Wrench
Safety Precautions:
1. PRIOR TO PERFORMING THIS PROCEDURE MAKE SURE THAT THE T/R SET IS DE-ENERGIZED AND LOCKED OUT USING THE PROPER INTERLOCK SEQUENCE. LOCK THE SWITCH HANDLE IN POSITION #1 (BOTH BUSHINGS GROUNDED).
2. A SEPARATE SOLID GROUND CONNECTION MUST BE MADE TO BOTH OF THE HIGH VOLTAGE BUS CONDUCTORS THAT FEED THE PRECIPITATOR. THIS IS ESSENTIAL SINCE REMOVING THE DOUBLE PACK WILL ALSO REMOVE THE INTERNAL GROUND SWITCH. IF SEPARATE EXTERNAL GROUND CONNECTIONS ARE NOT MADE, LETHAL VOLTAGES MAY EXIST WITHIN THE T/R SET.
Other Precautions:
1. Make sure that the lid of the T/R set and other surfaces are clean of dirt, flyash, water or other contaminants prior to opening the T/R set. Once the T/R lid is removed, care should be taken not to introduce any contaminants into the dielectric fluid.
2. It is NOT necessary to drain the dielectric fluid to perform this test. Draining the fluid will only cause other problems. This procedure is intended to be performed with the fluid at the operating level. If there are any questions concerning the type of fluid in the T/R set, check the dielectric nameplate on the side of the tank. Material Safety Data Sheets (MSDS) for all dielectric fluids are listed in the Resources tab on www.nwl.com.
Procedure:
1. Using a 9/16" wrench, remove the cover clamps on the handhole cover of the T/R set. When all the clamps are off, remove the cover. The switch handle and shaft will disengage from the switch upon removal of the cover.
2. Remove all of the electrical connections to the Double Pack. Refer to the diagram below. The connections are as follows:
- High Voltage Bushing connection: Two BNC connectors located near each end of the outermost printed circuit board on the Double Pack. Twist BNC connector to remove.
- High Voltage Transformer connection: Two BNC connectors located on the corners of the innermost printed circuit board of the Double Pack.
- Feedback connection: One Mate-N-Lock quick disconnect plug located in the center of the outermost printed circuit board on the Double Pack. Press the release tabs on each end of the plug and pull.
3. Using a 11/16" wrench, remove the mounting nuts and hardware from the studs that secure each corner of the Double Pack to the mounting bracket.
4. Pull the Double Pack up and out of the tank.
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