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EMRs vs. SSRs

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EMRs vs SSRs

Life ExpectancyAcoustical NoiseOrientation/Shock/VibrationContact Bounce/ArcingElectromagnetic InterferenceHarsh EnvironmentsInput Power ConsumptionSwitching SpeedSwitching CharacteristicsThermal ConsiderationsCost

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Life Expectancy

Correctly applied, SSRs have nearly unlimited life vs 100K cycles for EMRs.SSRs Made time proportioning control possibleExtensive Application in Plastic extruders & molders

Life

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Acoustic Noise

Acoustic Noise is a problem with EMRs, particularly contactorsOffice machinesMedical devicesHome applicationsCopiersLighting ControlTankless water heaters

Noise

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Orientation, Shock, Vibration

SSRs are Able to operate in any positionAllows Best utilization of mounting spaceBackplanes, I-beams, etc.SSRs withstand high shock values without interfering with their operationSSRs withstand significant vibration without operating problems

Orient

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Contact Bounce/Arcing

No Arcing or pitting of relay contacts with SSRs, which is significant with very light or very heavy loadsNo electrical transients created due to arcing or disruption of magnetic fieldsNo Wear out of the switching elementMachine tool industry

Wear

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Electromagnetic Interference

Electrical interference created by switching inductive loads can cause false signaling in the control system , or other controlsMany “glitches” traced to electrical noise on the lineEuropean Noise compliance-CE ratingSSRs also are not impacted by near by magnetic fields.

EMI

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Harsh Environments

SSRs are impervious to atmospheric contaminantsRemote locations, Unmanned stationsAntenna positioningCell phone relay stationsRemote instrumentation

Env

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Input Power Consumption

Can run many relays with far less power than EMRCan control 125A with less than 20mA of current….. microprocessor compatibleControl panels,battery powered systems

Power

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Switching Speed

Can turn on in .02 mS (random versions) , or ½ cycle (zero-cross)Necessary for positioning and plotting applications along with lighting

Speed

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Switching Characteristics

SSRs include zero current turn offSSRs offer either random or zero voltage turn onEMRs are only random turn on and random turn off

switch

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Thermal Considerations

Panel mount SSRs require external heat sinks.Heat Sinks add cost and take up space.PC mount SSRs are stand alone and don’t require heat sinks.DIN Rail mount SSRs have integral heat sinks.EMRs don’t require heat sinks.

Heat

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Cost

Cost of a SSR is usually higher than an EMRValue of SSR’s is dependent on the application Knowledge of the application is the most important part of the saleCross referencing and drawing take-offs are tricky

Cost

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Disadvantages of SSR’s

Heat SinksInitial purchase cost

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Advantages of SSR’s

Unlimited LifetimeOperates Regardless of OrientationHarsh Environments – No ProblemLow Input Power ConsumptionReduced Electromagnetic InterferenceNo Audible NoiseLogic CompatibleNo Contact Wear or BounceControlled Turn On/Off characteristics

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EMRs vs SSRs ???

Based upon performance, SSRs are way ahead.Based upon cost, EMRs are way ahead.Both products have valid applications.

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Why Crydom?

The market innovator and leader since 1970World wide representationContinual major capital investment in plantOver 1000 standard designs

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Extensive design capabilities for custom productsSkilled personnel focused on your requirements Only manufacture SSRsAll products manufactured to UL, CSA, VDE & TUV

Why Crydom?