The Safety Contactors Or Limit Switches - Etesia HYDRO 124D Technical Training Manual

The safety contactors or limit switches

Their aim is to give information on the condition or position of a part, of a system. There are
4 types on the Hydro124D :
- plunger-type contactors : they are activated by a translation movement
- roller-type contactors : they are activated by a rotational movement
- flat contactor (seat) : it is activated by pressure on its surface.
The roller and plunger contactors can be connected in two different ways depending on
whether we wish to have a closed contact when the contactor is at rest (1) ("break") or when
it is activated (2) ("make").
Part / function Type of
contactor
Cutting deck Plunger
Parking brake Roller
Seat Flat
Neutral point Roller
Cutting height Plunger
adjustment (new
cutting heights)
Fixed grassbox Roller
Mobile grassbox Plunger
Flap ram Earthing
Electro-ram Of no
importance
Grassbox Roller type
These are the first components to check before any closer examination when one or
more functions are not working.
The contactors have no polarity : the way the cables are connected has no influence on
their operation.
All the contactors are adjustable (except those of the seat and the flap ram).
Quantity Type Situation
2 Closing To the left and right of the cutting deck (informs
of the presence of the removable side parts)
1 Opening Under the footboard to the left of the steering
console (informs of the condition of the parking
brake)
1 Closing Under the seat cushion (informs of the
presence of the driver).
1 Closing Under the engine cover, between the fan and
the engine (informs of the position at dead
centre)
1 Opening Under the engine cover, above the electro-ram
(informs if the plate is at the bottom upper
position to stop downward movement of the
cutting deck)
1 Closing Above the fixed part of the basket (informs on
the position of the grassbox unit)
1 Closing To the right of the grassbox (informs on the
position of the mobile part of the grassbox)
2 Closing On the right flap ram, at each end of the ram
(informs on the position of the flap).
2 Of no In the electro-jack (allowing the electrical stop
importance at "out" and "in" end of travel)
1 Closing At the back of the cutting deck (informs on how
full the grassbox is by activating a buzzer)
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