Hammond master service manual

Page 2

SAFETY NOTICE

Great care has been taken In the design and manufacture of this product to assure that no
shock hazard exists on any exposed metal parts. Internal service operations can expose the
technician to hazardous line voltages and accldentaliy cause these voltages to appear on
exposed metal parts during repair or reassembly of product components. To prevent this. work
on these products should only be perlormed by those who are thoroughly lamiiiar with the
precautions necessary when worklng on this type of equipment.

To protect the user, it is requlred that all enclosure parts and safety interlocks be restored to
their orlglnal condltlon and the fellowlng tests be performed before returnlng the product to
the owner after any servlcs operation.

Plug the AC ilne cord directly Into a line voltage AC receptacle (do not use an Isolation
transformer for this test) and turn the product on. Connect the network (as shown below) In
series with all exposed metal parts and a known earth ground such as a water pipe or condult.
Use an AC VOM of 5,000 ohms per volt or hlgher sensltlvlty to measure the voltage drop across
the network. Move the network connection to each exposed metal part (metal chassis. screw
heads. knobs and control shafts. escutcheon. etc.) and measure the voltage drop across the
network. Reverse the line plug and repeat the measurements. Any reading of 4 volts HMS or
more Is excessive and Indicates a potential shock hazard which must be corrected belore
returnlng the product to the user.

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AC SCALE

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CERIHIC RF
BYPISS CIP

TESI CLIPS

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PROBE

CONNECIED 10 M0
[Milli GROUND

T0 EXPOSED IE1. PINS