Siemens Building Technologies
CA2N5241E / 11.1998
Landis & Staefa Division
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5
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Digital time switch
BUD
Digital time switch used to switch plant on and off, or for the control
of setback periods at night and weekends.
Suitable for mounting on DIN rails
Quartz-controlled microprocessor time switch
Simple programming
Manual on/off control
Holiday programming of up to 45 days
Digital input and digital display of clock functions
Summer/winter change-over
Scope for checking programmed switch times and making individual corrections
Power reserve of 72 hours
The microprocessor automatically stores the programmed times in chronological order.
The time switch operates in one of three modes: continuously On, continuously Off or
operated automatically via the time programme.
The power supply is buffered by a memory back-up capacitor. In the event of a power
failure the clock will continue to run, with the programme retained, for 72 hours.
However, the relay will go to (or remain in) the normal position (71 / 72 made).
When placing an order, please specify the quantity, product description and type code.
Example: 2 Digital time switches BUD
Sheet steel housing, printed circuit board with LCD display and programming buttons.
Mounting instructions (Ref. 35654) are enclosed with the digital time switch.
Although microprocessor protection is provided, unusually strong electromagnetic fields
could cause interference.
To avoid interference:
– The device should not be installed close to inductive components
– A separate AC 24 V supply must be provided (if necessary use a mains filter)
– Inductive components must be fitted with interference suppressors (varistor / RC unit)
After clearing the cause of interference, the time switch must be reset.
– The connection terminals must be freely accessible.
– Ensure adequate air circulation to dissipate the heat generated during operation.
– Snap-on rail mounting. Rail type: EN50022-35x7.5
– 4 clear holes are provided for surface mounting
Functions
Ordering
Construction
Mounting notes
Mounting
