HBControls Solid State Relay Assemblies

HBControls has developed a family of solid state relay and heat sink assemblies which virtually eliminate the need for any thermal engineering on the part of the design engineer. The assemblies include a convenient DIN rail mounting configuration, finger-safe covers and utilize the highest quality relays available. All of the relays used in the assemblies have received UL, CSA, VDE and CE certification.

Mercury and Mechanical Vs. Solid State Relays:

Mercury: Solid state: EMR:

Contains no mercury                                                               No                   Yes                  Yes
Provide air gap isolation:                                                        Yes                  No                   Yes
Photo-coupled isolation of input to output                             No                   Yes                  No
Can accommodate high inrush well                                        Yes                  Yes                  No
Does not have arcing                                                              Yes                  Yes                  No
Quiet operation                                                                       Yes                  Yes                  No
Silent operation                                                                       No                   Yes                  No
Environmentally friendly                                                        No                   Yes                  Yes
Can be mounted at any angle                                                 No                   Yes                  Yes
Does not produce heat or require a heat sink                          Yes                  No                   Yes
Available as a hybrid                                                             No                   Yes                  Yes
Can be used in hazardous environments                                 Yes                  Yes                  Yes
Extremely fast switching                                                        No                   Yes                  No
Is well suited for proportional power control                         No                   Yes                  No
Can be used for phase angle control                                       No                   Yes                  No
Can be exported to other countries easily                               No                   Yes                  Yes
RoHS                                                                                      No                   Yes                  Yes
Millions of operations                                                             Yes                  Yes                  No
Billions of operations                                                             No                   Yes                  No
Contains no moving parts                                                       No                   Yes                  No
Little to no leakage current/voltage w/o snubber                    Yes                  Yes                  Yes
Has input currents as low as 2 mA                                         No                   Yes                  No
Has no inrush on input terminals                                            No                   Yes                  No
Current limited control input available                                   No                   Yes                  No
Fast switching time                                                                 No                   Yes                  No
Easily disposed of                                                                   No                   Yes                  Yes
Consumes minimal power, Input side                                     No                   Yes                  No
Consumes minimal power, output side                                   Yes                  Yes                  Yes
Consumes no power on output side                                        Yes                  No                   Yes
Can be used in variable power applications to save energy    No                   Yes                  No
Risk of fines due to improper handling and disposal             Yes                  No                   No
Universal acceptability globally                                              No                   Yes                  Yes
Easily compatible with industrial control components           No                   Yes                  Yes
Finger safe operation                                                              No                   Yes                  Yes

We are frequently asked to recommend our solid-state relay assembly in replacement of a mercury or electromechanical relay or contactor. Often the only application information provided is the contact rating of the relay currently being used, while this information is helpful it is incomplete. It is imperative that the actual load being controlled, and the ambient operating temperature is known when applying a solid-state relay.

Solid-state relays, unlike mercury or electromechanical relays, do not have moving parts which wear out due to mechanical wear over a finite number of operations, theoretically, when properly applied, they infinite life. It is important therefore, that in addition to the current and voltage all characteristics of the load are considered. Is the load resistive or inductive, AC or DC, three phase or single phase. If three phase, are all three or only two legs being controlled, is the circuit Delta or Y? A major enemy of the solid-state relay and often the cause of premature failure is heat, when the relay is switching a load it is generating an amount of heat proportional to the wattage of that load.

When replacing a mercury or electromechanical relay with a solid state relay make sure that you have determined the actual load being switched as well as the ambient temperature of the environment in which the relay is being operated. Generally, if the load is greater than 10 amperes AC and the ambient temperature is greater than 20 degrees centigrade the relay must be mounted on an appropriately sized heat sink, or another method of directing heat away from the relay utilized. In the case of larger current loads, or a higher ambient temperature, both a heat sink and cooling fan may be required to direct heat away from the assembly.

HBControls engineers are well versed in the practice of determining the appropriate combination of solid-state relay and heat dissipating devices.