Hobart 5359D Operation And Maintenance Manual page 127

OM 2012
load iridicatirlg Jisht (9, Fig. 21 mus
dition.
(35) i!.ecJcrce Joad tc normcl. Turn off ind
Fig. 2).
icGtirt3 ligltt by prcxing reset s:,:?ch (7,
(36). Check engin e oil pressure at govemed speed (2000 Rr?l~<).' Gage slroufd indicate
at Jeust 38 PSI when the engine is hot. Check engine
cotilant
ten+xture.
Gage should indicate in the range of .I80 degrees to l?G degrees dependins
upon an?bient temperature.
(37) Check operation of fuse interlock (Ref. 7-J; 2, Fig. 10). W{fJl
unit 0pera:ic-g normaliy under load, remove protective relay circuit fuse (Ref.
11, Fig. 2).
The load contactor sllould open immediately. This indicates
that the fuse interlock reJay is functioning properly. Rep&e fuse and appiy
load.
NOTE: Make all protective refay tests with the unit operating urder load.
_ .
(38) Check operation of overvoltage relay and indicating fight.
. (a) With tho unit running ct normal loud, adjust' the voltage regulator rheo-
stat (37, Fig. 2) to increase voltage (turn cfock\h:isc) until the,overvoltage
sensing re!ay actuates the protective monitor to open the load conthctor
and turn
on
the overvoitagc indicating light. The ovetvoltase xnsing
relay should trip when voltage
reaches
130 V to 134 V.
(b) Return unit to normal operating conditions by adjusting voltcge regulator
rheostut and pressing reset switch (7).
/
' (39)
Ch ec. o era ion of undervoltage sensing relay, indicating light, und time delay.
k p t
Before starting this check, Jet us understand the sequence of events which should
happen when voltage is reduced to 103 V or lower.
At some value between 103
V and 93 V, the undervoltage sensing relay (Ref. J-J; 5, Fig. JO)
should function to activate the undervoltcge time delay circuit. Five seconds
after the time delay circuit
is
activated, (if the under-voltage condition con-
tinues) it should function to open the protective monitor relay which, in turn,
will open the load contactor to stop powerdelivery. As a resuJt of the action,
the undervoltage indicating JiglIt (9) should be turned ON. A stopwatch or
sweep-second-hand watch is required for this check.
Proceed as fof Jaws:
(a) With unit running at normal load, use the voltage regulator rheostat (37,
Fig. 2) to reduce voltage to 104 V. The load contactor should NOT
open
after a Ssecond dalay .
Aug 25105
2-3
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