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(iv) The dynamo driving belt tension should be checked carefully A
slack belt overheats, causes low dynamo output and may work
off the pulleys A tight belt leads to early belt and dynamo
bearing failure The belt tension must be sufficient to ensure
that the slack side does not sag, fluctuate or bulge away from
the pulley when the engine is running. With the engine stopped,
the belt tension may be set by loosening the dynamo pivots and
adjusting strap Ensure that they are tightened again after
adjustment.
When correctly tensioned, the belt will feel tighter than a
conventional V-belt
(v) As the rotation of the dynamo is critical, ensure that it is correct
when related to the engine An arrow is stamped on the dynamo
casing The engine rotation is clockwise when viewed from the
flywheel end A reverse rotation dynamo is available from Petters
Ltd or their agents.
Lubrication
(b)
Bearings are lubricated on assembly and require no attention between
overhaul periods
Terminals
(c)
Main terminals and all circuit connections must beclean and tight.
Terminal shrouds should be in position.
(d) Brush gear
Remove the cover and inspect the brushes and commutator Brushes
should be free in their slides Springs should seat squarely on the
brushes See that the insulation is in good condition The brushes and
commutator should be free from dust and grease and contact surfaces
clean, smooth and uniform in colour.
(e) Wiring
(i) A cable harness is supplied by PettersLtd, but if this is found to be
of insufficient length for the installation it may be extended by
using the appropriate wire and insulated connectors
(ii) As the instrument box is flexibly mounted, an earth lead has been
included in the cable harness to link the instrument box to the
dynamo If the dynamo and engine are not secured to a common
base. it is advisable to link these units with an earth lead.
RegulatorAdjustments should not be made other than by an
electrical engineer.
86. Protection and preservation
(a) Covers
When not in use engines should be protected by a waterproof cover
Under tropical conditions a permanent awning should be provided.
(b) Storage
Before dispatch from the factory engines are preserved for storage and
should not be disturbed until required for use.
(c) Intermittent use
When not in regular use engines should be run for a thirty minute
period each week to lubricate internal parts and boil off any
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