Hofmann Snap-on Y2k, Руководство по обслуживанию

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Removal and fitting of the vibratory assemblies
Tools required: Hexagon keys 2.5 and 5 mm,
open-end wrench 17-mm width across flats,
½" drive hexagon socket wrench 6-mm across flats 140 mm long (DIN 7422).
For removal undo, for installation fasten the following connections:
a) With hand drive: Two receptacles from shaft band brake solenoid Y4.
With motor drive: Motor connector X42 (4-positions) at Power Interface board.
b) Connector X3 (16-positions) of the ribbon cable for the Optoelectronic unit, the
unbalance transducers and temperature sensor at the Controller Board.
c) Unscrew the two hexagon socket screws M4 (2.5-mm width across flats) at the rear
leaf spring and take the spring off. Slacken nut (17 mm across flats), then screw back
hexagon socket screw (5 mm width across flats) for 3 mm. Support the transducer at
the same time, not to trop the steel balls, placed at both ends of the transducer.
d) Three caps of black plastic at the front of cabinet.
e) Six hexagon-socket screws M8 (6-mm width across flats) at the cabinet (Torque 23
Nm).
15.2 Unbalance transducers and temperature sensor
Two transducers (
Snap-on
P/N EAA0260D59A, HOFMANN Mat-Nr. 6717253) and the
accompanying temperature sensor are used with all variants of the Y2k vibratory assemblies.
The alternating forces, produced during rotation of the unbalance, are converted into a
proportional electrical charge utilising the piezo effect. Charge amplifiers on the processor
board convert the transducer outputs to alternating voltages.
A transducer consists of a single piezo disc with contact plates; insulation discs
and thrust spreading members at both sides of it. This sandwiched arrangement is
encapsulated by a moulded case of black plastic. The slotted terminal strips of the
two contact plates jut out of the plastic case, protected by collars.
Connection to plug X3 is via the wire harness (
Snap-on
P/N EAW0239D00A,
HOFMANN Mat-Nr. 6792035), by means of insulation displacement.
The wires from position 12 and 16 of connector X3 are marked with a small black bush and
have to be connected to the transducer terminals marked with the embossed
+
. Wires 11 and
12 of X3 hook up transducer B3 located at the front, wires 15 and 16, connect transducer B2
at the rear of the vibratory assembly.
To make the insulation displacement connection to the transducer, proceed as follows:
a) To connect a transducer to an already used wire harness, cut off the wire ends at the
notches.
b) Check the position of the terminal strips relative to the surrounding collar.
If the pointed ends of the terminal strip 0,6-mm below the edge of the collar, contact
problems can arise.
c) Brake off the two small plugs, formed with the moulding process of the transducer case.
d) The insulated wire of the ribbon cable is put in the slot at the collar of the transducer, with
the end protruding about 3-mm over the collar.
e) The plug, with the slot aligned to the wire, is placed upon the collar and then pushed into
the collar, to be level with the edge.
The narrow slot in the terminal strip will cut the insulation and a gas-tight bond is formed
between the tinned copper wire and the contact strip.
A capacitance meter across positions 11 and 12 respectively 15 and 16 of the unplugged
connector X3 should read in the range of 1700 to 2100 pF. The resistance across the same
positions and the insulation to the force spreading members should be more than 10
9
Ohms.
Service code C75 (
JBC 8500
F64) or a special high-resistance measurement instrument has to
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