Panasonic is part of a large worldwide groupselling relays and associated switching products under different brand names in different territories.The conditions of use in some territories may differ from those customary in Europe. In particular there are often major differences in regard to national and international specifications, such as UL, CSA, VDE, SEV, EVE, SEMKO, etc. Thus, when considering contact loads as stated in this catalogue (e.g. 10 A, 30 VDC for the SP relay) its hould be understood that these values are not necessarily an absolute maximum but tested ratings. Mostly the stated value has been tested for a certain life expectancy as stated by the manufacturer or the respective test house. Thus, under different conditions, the stated “maximum” may, in practice, be safely exceeded.
For repairable products, their
serviceability aintainability another
problem. esign reliability
H factor, redundancy,
fo l-proof, fail-safe
[2] RELIABILITY MEASURES
The following list contains some the
most popular reliability measures:
R eliability measure
Sample
representation
Degree reliability R(T) 99.
Sometimes MTBF used represent
the service lifetime before failure.
22 ds_x61_en_relay_technical_information_091112D
. For
example, none light bulbs has
failed for 100 hours, the degree of
reliability defined in, 100 hours tim is
10/10 100%.
Percent/count normally used for relays. indicates the mean tim period
until product becomes faulty MTTF
normally applies unrepairable products
such parts and materials.
4. indicates the mean
tim period which system,
equipment, part operates normally
between two incidences repair. hen product
has broken down, the user may throw it
Reliability
(broad sense)
away repair it.
2 lia ility e
T rm
Every product has finite service lifetime. lia bility (narrow sense), durability
Long life tim TTF, 10, R(T),
L failure rate: Lam (^), MTBF
2. In
the relay industry, reliability use has a
significance aspects servicing. F
MTBF acronym mean time
between failures.
Failure rate often represented the
unit percent/hours.Reliability
RELIABILITY
[1] WHAT RELIABILITY?
1.
3. F
MTTF acronym mean tim to
failure. addition, reliability product
design becoming serious concern for
the manufacturing industry.
The relay one such objective of
MTTF. lia ility
Degree reliability represents
percentage ratio reliability. The reliability of
repairable products recognized as
“reliability broad sense the term ”.
The JIS Z8115 standard defines the
degree reliability follows:
The probability which system,
equipment, part provides the specified
functions over the intended duration
under the specified conditions. For parts with low
failure rates, “failure unit (Fit) 10-9 /
hour” often used instead failure rate.e. lia ility lia ility
o e
Reliability “built” into products. short,
reliability has three senses: i.
Product reliability the user's site is
called “reliability use”, which consists
mainly reliability the broad sense. reliability
of the product itself, serviceability the
product, and reliability product design. MTBF
only applies repairable products.
Availability
3.
MTBF tells how long product can be
used without the need for repair.
This means that product can continue
normal service infinitely. This is
referred intrinsic reliability which
consists mainly reliability the narrow
sense.9%
MTBF 100 hours
MTTF 100 hours
Failure rate fit, /hour
Safe life B10 hours
(b) MTTF
(c) Safe life
1. only three bulbs
remained alive, the degree reliability is
3/10 30%.
Mean failure rate defined follows:
Mean failure rate Total failure count/
total operating hours
In general, failure rate refers to
momentary failure rate. lia ility e
T rm
In the industrial world, reliability an
index how long particular product
serves without failure. aintainability
M TTR
P reven tive aintenance, predicted
m aintenance
3. This represents
the probability which system,
equipment, part, which has continued
normal operation certain point of
time, becomes faulty the subsequent
specified tim period. ilu te
Failure rate includes mean failure rate
and entary failure rate.
1.
2
