The following is the high-level summary of a "110V/220V Dual Voltage Architecture" proposal we presented to an international multi-million Hotel Casino resort. The same "concept" can be applied to many different customer applications:

1. Receptacles to Support Dual Voltages

          

     WF-2.R4T.R5A           Side View with Utility Box

 

The above is the top view and the side view of a set of WF-2.R4T.R5A wall outlet, will support both 220V and 110V receptacles inside the same WF-2 frame. 

·         R4T:   220 volt Universal Receptacle

This receptacle accepts all 220 volt plugs from any country. It accepts the Chinese style 220 volt plug (2 parallel flat power prongs). It provides grounding for all plugs except the "Schuko" plug  (i.e.,  no grounding for the German/French plug).

·         R5A:   110 volt Uni-Receptacle

This receptacle accepts the US/Canada/Taiwan style 110 volt plugs (2 flat power prongs, maybe “polarized” so one end is slightly bigger).
Note that there will be a “110V” label imprinted on the R5A to clearly indicate this is the 110V receptacle – to protect casino/hotel guest’s 110 volt electrical equipments.

 

The following lists the components in a WF-2.R4T.R5A set:

                        

   WF-2  Frame          WF-2.UtilityBox              R4T                R5A

   

Note that the receptacles have two versions:  10 Amp or 20 Amp

               

     10A 250V       20A  250V

2.  Wiring to Support Dual Voltages

In a standard building construction, 3 wires are required to support one voltage. To support 2 voltages, both the 110V and the 220V,        4 wires are needed:

·         Ground Wire "E" - usually Green

The Ground Wire can be shared between 110V and 220V

Connected to the R4T and then the R5A receptacle in tandem

·         Neutral Wire "N" - usually White or Blue

The Neutral Wire can be shared between 110V and 220V

Connected to the R4T and then the R5A receptacle in tandem

·         Hot Wire "L" - usually Black or Brown

The Hot Wire can NOT be shared between 110V and 220V

220V wire – use the Brown wire, connect to the R4T receptacle separately

110V wire – use the Black wire, connect it to the R5A receptacle separately

The above analysis shows that 33% more wiring (from 3 wires to 4 wires) is required to support dual voltages in the same room, not 100% more wiring.

The following shows how to connect two R4T's in tandem:

3.  Alternative Receptacle Configurations

The following shows a different receptacle configuration: two 220V R4T receptacles in one frame, and two 110V receptacles in a separate frame:

                       

    WF-2.R4T.R4T                 WF-2.R5A.R5A 

 

In addition, the Ru4T receptacle can be used instead of the R4T receptacle:       

                

   WF-2.Ru4T.R5A             Ru4T

 

·         Ru4T:   220 volt Universal Receptacle

Same as R4T except it prevents the US/Japanese style 110 volt plugs with two parallel flat prongs from being accidentally inserted into this 220 volt receptacle. This can be a better choice to support the two different universal power strips as discussed in the previous section.

4.  Universal Power Strips to Support Dual Voltages