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6.2 Functional description
ASHCROFT
®
“ON-OFF“ level switches use reed switches magnetic sensors. This type of contact, hermetically sealed,
inert gas filled, are placed inside the slide bar and switched-on when the magnetic float reaches the commutating area.
The stroke of each float is limited to the height of the controlled level by suitable ring stops.
The “reed switch“ contact is made of two low-reluctance magnetic foils, placed inside of a glass bulb in order to be
protected by the dust, corrosion and oxidation. The inert gas inside the glass bulb is an additional protection against the
oxidation of the contact.
The “reed switch” contacts can be operated up to one million operations at full resistive load, providing its electrical limits
are respected. Auxiliary relays would be necessary for power circuits, as well as current snubbers / suppressors, to
safeguard the efficiency of the contacts.
The “reed switch” contacts may be, single contact type, “SPST”, or changeover type, “SPDT”.
The “SPST” contact can be selected either as “normally closed (NC)” or “normally open (NO)“ form.
6.3 Description of the components
6.3.1 Reed contact
The Reed contact is hermetically sealed and filled with an inert gas. See table maximum current (see chap.4.1)
The standard condition (if normally open or normally closed) of the Reed contact is specified by the customer.
6.3.2 Float
The floats are swimming on top of the fluid and contain a magnet which allows to open or close the Reed contact circuit.
6.3.3 Stem / Slide bar
Inside the slide bar, the reed contacts are wired and secured against slipping by casting the tube with a 2k epoxy
resin.
6.3.4 Top/low lever stop ring (Seeger ring)
The top or low lever stop ring are SEEGER
®
Locking Rings. The rings are limiting the heights of the controlled level.
7
Transportation
The device must be protected against impact and bending. The device shall only be transported in a cleaned condition
(free of residual media).
7.1 Delivery
The delivery is to be checked for completeness and transport damage. In case of transport damage, the delivery is not
to be accepted or only with reservation, the extent of damage is to be noted and, if necessary, a complaint is to be
initiated. In these cases, please contact our service department.
7.2 Storage
The storage of the devices should exclude external influences as far as possible to avoid damage to the devices.
Vibrations or impact effects must be avoided, and the limit values of the storage temperatures must be taken into
account.
Permissible storage temperature: -60 to +80°C
