THE ABCs OF POWER CONDITIONING
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Transcript of THE ABCs OF POWER CONDITIONING
THE ABCs OFPOWER CONDITIONING
A Simplified Approach to Understanding Power Quality
Problems and How to Solve Them.
Where Do Power Quality Problems Start?
• Disturbances are generated external to a facility.
• Disturbances are generated internal to a facility.
The Four D’s of Power Disturbances
• Destruction– High energy
– Short duration
– Visible evidence
– Easy to establish cause and effect
The Four D’s of Power Disturbances
• Degradation– Low energy
– Constant exposure
– Cumulative damage
– No visible evidence
– Electronic rust
The Four D’s of Power Disturbances
• Disruption– Low energy– Interferes with
operation of logic circuits
– Lockups, reboots, program dumps
– No trouble found system failures
– Frustration
The Four D’s of Power Disturbances
• Dynamics– Noise that can be heard
– Noise that can be seen
– Noise that interferes with the enjoyment of the production, performance, or meeting
There are two pathways
Normal ModePhase (hot) to Neutral
Should be <10 volts
Common ModeNeutral to Ground
Should be < ½ volt
The Nature of Power Problems
• 10% of problems are outages
• 90% are noise, voltage surges, harmonics, etc.
• It’s what you don’t see that can kill you
10%
90%
Common Mode Voltage
• Voltage measured neutral to ground– Voltage spikes– Conducted noise– Radiated noise– Unbalanced electrical distribution– Circuit loading
Voltage Sags and Swells
• Short term (less than 1 minute) decrease or increase in line voltage
• Variety of causes both internal and external
• Most modern loads are relatively immune
D – The Voltage Regulator
• Variety of technologies– Ferroresonant (undesirable for modern gear)– Tap switching autoformer (better)– Tap switching isolation transformer (better yet)– Electronic regulator with isolated output (best
bet)
Power Outages
• Complete loss of power for seconds to hours in duration
• Usually the result of a power company failure although may have internal facility causes, too.
E – The Uninterruptible Power Supply (UPS)
• Converts chemical energy stored in batteries to electrical energy to power the load
• A variety of technologies (standby, line interactive, on line
• Some are power conditioned some are not
• BUYER BEWARE!
If You Need a UPS
• It should be sine wave inverter design
• Inverter topology depends on the gear and application (standby or on line)
• Must have an isolation transformer if you want it to also provide power conditioning
An Integrated Approach
• Using an integrated ABCs approach will– Prevent destruction, degradation, and disruption
and safeguard dynamics– Protect from the full range of power quality
problems that affect your systems– Improve system performance– Reduce operating and repair costs– Increase satisfaction