These are not cheap $20 to $30 but if you brought the issue up maybe a change order.How it Works
How the Tamper Resistant Receptacle Works.
As shown in Figure 1, Switch "A" energizes the left hand Contact "B" and Switch "C" energizes the right hand Contact "D." The same arrangement applies to the lower portion of the outlet.
If, for example, a metallic object is inserted into the left power Contact "B" only, the object is not energized because it requires the additional insertion of a similar object in the opposite Contact "D" to move the slider to close Switch "A."
Similarly, if an object is inserted into the right hand slot only, it cannot become energized unless an additional object is inserted in the opposite slot to close Switch "C."
In other words it requires the presence of an object in both right and left hand contacts to energize the device. This condition is in practice fulfilled only by the insertion of the proper electrical plug as shown in Figure 2.
Remember, this receptacle can be used with either a 2 or 3 wire plug.
No other tamper resistant receptacle on the market can provide you with greater reliability and durability that the Hubbell Hospital Grade tamper resistant Receptacle.