89750147 Crouzet USA, 89750147 Datasheet - Page 272

• Manufacturer Part Number: 89750147
• Description: STAINLESS SLEEVE-MILL TEMP PRB
• Manufacturer: Crouzet USA

Specifications of 89750147

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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➜ Between 2 differents circuits
The individual accuracy of any given unit and the scatter caused by the
cutting or adjustment of the cams mean that we have to allow for a certain
tolerance between the theoretical diagram and that actually obtained.
When plotting the theoretical diagram, there are two possible eventualities:
■
■
A copy (a photocopy or dyeline print)) of the diagram shown below on
page 273 will enable you to give us details of the particular profile to be
cut in our works.The changeover points will need to be entered in degrees
with due allowance for the characteristics of the timer selected. The cams
are fitted in ascending numerical order reading away from the drive motor.
There are vast numbers of possible applications for these timers.
In the commonest application, the timer performs repeated cycles which
cause contacts to be closed for fixed lengths of time.
It may also perform a single cycle but the program is still a function of
time in this case.
➜ Examples:
lubrication, animated shop-window displays, staged start-up of sets of
pumps, automatic presses, industrial washing machines,etc.
The above applications are termed "open-ended" because the sequential
progress of the operations is dependent solely on time and there is no
check that the operation called for has actually taken place.
The main application for timers is in sequential automatic control systems
where a check on the completion of an operation causes the next
operation to begin (limit switch, thermostat, timeclock). When this is the
case the timer is used in the step by step mode. The program is not run
as a function of time but in response to external commands, and the
motor merely serves to move the program forward in steps.
Step by step applications of this kind are in fact the ones for which timers
can most usefully be employed. Though often decried, they allow
automatic control systems to be greatly simplified and much of the
hardware, such as relays and memories, needed for other techniques to
be dispensed with.
In the same unit, the timer may control not only switching operations
which follow one another in a precise order but also series of step by step
sequences and sequences proportional to time, sequences run in two
directions, and so on.
The circuits used are simple and there is a special technique for them
which is easily modelled.
If the power fails, the timers may either:
■
■
➜ Examples of step by step applications
Control of machine tools, preselection counters, automatic car parks,
vulcanising presses, systems for feeding livestock, etc.
Applications
Utilisation
it is absolutely essential that the chronological order of the changes of
state is maintained (Fig.A). When this is the case, the diagram interval
between two switching operations must be at least equal to the accuracy.
the chronological order of the changes of states need not be
maintained (Fig. B)
remain in position, in which case the orders given are held in store,
which is an intrinsic feature of the device, or
return to their starting point as soon as the power comes back on.
The cycle then begins again from the beginning.
X°
f|x-y|
A
Y°
movement of automatic milling machine tables, periodic
X°
B
Y°
Undefined
(see page 284)
accuracy of any
given unit
= individual
See page 284.
Our timers are generally designed according to international standards,
IEC, American standards (UL-CSA) and/or European standards (EN),
VDE etc.
➜ Quality control
Our products are quality controlled systematically during assembly and
on completion. The overseeing of control checks in the workshop, the
use of data collected and possible product assessments which can
occur form the essential role of Quality Control. All our products
undergo a final check, either at 100% or on a selective basis following
French standard X 06-022, which provides for a classification of
possible defects in 3 groups : critical, major, minor.
Different tolerance thresholds (matching necessarily varied statistical
analyses) are thus determined as a function of the possible
repercussions of any anomalies during the life of the product in normal
use, such as defined in the preceding sections. The size of the batches,
the sampling quantities and the standards selected combine to define
the thresholds.
➜ Note:
According to customer requirements and for certain product ranges
which must meet specific needs expressed in a specification, it is
always possible to create or to modify a quality standard on a normal or
special existing product and to vary the level of inspection. It can
happen that the tolerance level is set at zero for certain parameters
directly linked to the completion of a function for which total success
must be assured : a defect is therefore fatal. Such specific requirements
do, however, lead to a significant increase in product costs.
Some typical circuits
Standards and approvals
Quality
E
xemples de branchement
Normes et homologations
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