www.asi-ez.com Selecting a DIN Rail mounted Power Supply can be tough. In this presentation,you will find suggestions on what to look for when selecting a power supply for your application.

1. What to Look for
When Choosing a
Power Supply
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Automation Systems
Interconnect
Safety, reliability,
and power factor
correction are
among the prime
considerations
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2. One of the most
fundamental and
often overlooked
purposes of a power
supply is to provide
isolation and
therefore safety from
a high-voltage (or
dangerous) supply line
Safety
First
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3. Reliability
Q: What Affects the Reliability
of a Power Supply?
A: - Average load rate
- Vibration
- Ambient
Temperature
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4. Key issue is the amount of
heat generated by the
internal components
ASI Power Supply
Designed with
Excellent
Ventilation to
Avoid
Overheating
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5. Mean Time Between Failure
(MTBF)
some manufacturers have developed
their own proprietary calculations for
MTBF that produce higher values, it is
best to compare only using the MTBF as
defined in MIL-HDBK-217E
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6. key
performance
element of a
power supply
is its power
factor
Power Factor Correction
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7. Power
Factor
Correction
There are two primary methods of power
factor correction (PFC). The first method
is the use of a simple coil at the input, and
the second involves the use of a special
electronic power-factor-correction circuit.
The use of the coil is referred to as "passive"
PFC and it typically produces a power factor
of 0.7 to 0.8. The best use of the available
energy with the least amount of
conducted harmonics can be achieved
with "active" PFC.
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8. Power
Factor
Correction
“Active” PFC
Active PFC can produce a power factor
greater than 95% and is most useful in
larger power supplies, 24 Vdc at 10 A and
higher, since the conducted harmonics are
directly proportional to the current load.
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9. Power
Factor
Correction
Look for the power supply to
also meet the EN 55011-B
and EN55022-B specification
for electrical emissions and
EN 61000.3.2 regarding
harmonic emissions
conducted back on the main
input lines.
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10. Surge
Protection
This built-in feature
(up to 4 kV of protection)
saves valuable panel space
by not requiring an
external suppressor
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11. A good power supply is
one that offers a
minimum of 5%, and
ideally 10% of overload
protection
.
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12. Short-circuit protection:
- For Safety Purposes
- Saves time in powering
up after a short circuit
has been detected
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13. Agency Approvals
UL, CSA, and CE
compliance marks are
evidence of passing
several safety and
electrical emissions
requirements
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14. Agency Approvals
The UL 508 listing offers the additional
benefit of not requiring a power supply
rated for twice the intended use. Without
UL 508, the power supply must be
derated by 50% in order for the control
cabinet to also be UL 508 compliant.
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15. Contact ASI
For More
Power Supply Information:
asi-ez.com
877-650-5160
sales@asi-ez.com
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