Mody Pumps G 706 TM - Manual (Page 7)

GALVANIC CORROSION PROTECTION (FOR SEA-WATER DUTY PUMPS ONLY)
THE PARTS OF THE "MODY" SUBMERSIBLE PUMP THAT ARE IN CONTACT WITH SEA- WATER
ARE PRIMARILY OF STAINLESS STEEL AND ALUMINUM. AS SEA-WATER IS AN ELECTROLYTE
THE PROBLEM OF GALVANIC CORROSION EXISTS DUE TO THE DIFFERENT ELECTRIC
POTENTIALS OF THE MATERIALS IN FLOWING SEA-WATER. TO PREVENT THIS, THE PUMPS
ARE EQUIPPED WITH ZINC ANODES FIXED ON THE OUTER CASING AND DIFFUSER. ZINC,
BEING THE LESS "NOBLE" METAL (MORE NEGATIVE POTENTIAL) GETS CORRODED THUS
PREVENTING CORROSION OF ALUMINUM AND STEEL. IT IS HOWEVER NECESSARY TO INSPECT
THE CONDITION OF THE REPLACEABLE ANODES PERIODICALLY AND REPLACE WHENEVER
NECESSARY. (TYPICALLY INSPECTION ONCE A YEAR SHOULD SUFFICE)
NON REPAIRABLE ITEMS
1. ALL "O" RINGS TO BE REPLACED WHENEVER PARTS ARE DISMANTLED.
2. SEAL ELASTOMER PARTS SHOULD NEVER BE RE-USED AFTER DIS-ASSEMBLY.
3. DO NOT REFILL BEARING GREASE. NEW BEARINGS MUST BE INSTALLED WITH SPECIAL
HIGH TEMPERATURE GREASE.
ELECTRICAL INFORMATION .
MOTORS ARE DESIGNED TO OPERATE ON SINGLE VOLTAGE AND FREQUENCY. MAXIMUM
DEVIATION IN VOLTAGE ALLOWED IS +/-6% AND FREQUENCY +/-3%. CHECK NAME PLATE FOR
OPERATING VOLTAGE AND FREQUENCY.
DISMANTLING AND OVERHAULING.
GENERAL OVERHAUL AND OIL CHECK. (REF. DRGS. NO.DW/042/00 (SHEETS 1 &
2) AND DW/043/00 (SHEETS 1 & 2)
1. ALWAYS REPLACE O-RINGS WITH NEW ONES WHENEVER DISMANTLING AND RE-ASSEMBLING
A PUMP. NEVER RE-USE OLD O-RINGS.
2. ALWAYS ISOLATE THE UNIT BEFORE REMOVING THE CABLE GLAND. BE CAREFUL WITH
O-RINGS AND SEALING SURFACES. PROTECT THE CHAMBER AGAINST RAIN AND MOISTURE.
3. DISCONNECT STATOR LEADS. SNIP OFF LEAD WIRE CONNECTORS AND UNSCREW EARTHING
SCREW. LOOSEN SCREWS, REMOVE CABLE GROMMET AND CABLE LEAD GROMMET. CLEAN THE
SEALING SURFACES CAREFULLY AND GREASE THE NEW O-RINGS BEFORE FITTING THE SAME.
DO NOT USE THE OLD O-RINGS.
4. LOOSEN HEX BOLTS AND LOCK WASHERS AND REMOVE BASE PLATE, STRAINER, DIFFUSER
CENTER, AND DIFFUSER HOLDER. PRY OUT DIFFUSER RING FROM OUTER CASING. THE
DRAWING SHOWS THESE DETAILS. CHECK BY HAND THAT THE ROTOR SHAFT IS NOT JAMMED.
5. PLACE THE PUMP ON THE BOTTOM STUDS. TAP THE OUTER CASING WITH NYLON
HAMMERS/MALLET TILL IT LOOSENS FROM THE TOP BRACKET. SEPARATE THE OUTER CASING
FROM THE TOP BRACKET BY EMPLOYING TWO SCREW DRIVERS AS LEVERS AND PUSH THE
OUTER CASING DOWNWARDS TILL IT STANDS ON THE FLOOR. LIFT THE UNIT BY THE
EYEBOLTS CLEAR OFF THE OUTER CASING.