You will see the Out 1 <-> E (54 V) is smaller , Out 2 <-> E (165 V) is larger this time.
54 V+ 165 V = 219 V
For the Shielding is not connected to the Earth:
Out 1 <---> Shielding only : 114 V
Out 2 <---> Shielding only : 104 V
114 V + 104 V = 218 V
Out 1 <---> Earth only : 217 V
Out 2 <---> Earth only : 11 V
217 V + 11 V = 228 V
Strange ... ???
According to the theory, the output of the Isolation Transformer does not form a Voltage Potential Difference with Earth. But there is ... ... so, I try the dangerous test ... ... measure the Electric Current between the Out 1 / Out 2 with the Earth.
Fortunately, the Electric Current is ZERO ... ... this shows that the Voltage Potential Difference may be due to Capacitive Coupling. In other words, it is theoretically safe for touching.
Please DO NOT touch the output of the Isolation Transformer even it is THEORETICALLY safe. Please refer to here.
Moreover, the test shows that the Placement of the Isolation Transformer may affect the Capacitive Coupling effect. And one of the suggestions is that, keep the installation plate and screws insulated. |
