In this article, we aim to clarify a common query raised by installers regarding a 60V reading when using certain testers, such as the TIS tester, during Zappi installations. This reading can sometimes be misinterpreted as a fault, but in reality, it is a harmless by-product of modern switch-mode power supplies. Below, we explain the nature of this voltage and why it should not be a cause for concern.
What is the Floating Voltage?
The 60V reading is a floating voltage, commonly observed in switch-mode power supplies. This type of voltage is residual and does not represent any actual current flow—meaning no amperage is involved. Essentially, it is a remnant voltage that does not carry the power necessary to cause harm or signal a malfunction.
Why Does the Floating Voltage Appear?
When the Zappi’s relays are not engaged, this floating voltage may be present. However, once the relays engage and the Zappi begins to operate normally, this floating voltage dissipates completely. It is simply a by-product of the way switch-mode power supplies are designed and is a normal, expected occurrence.
Impact on EV Testers, Specifically TIS Testers
Although this floating voltage is harmless and does not pose any safety risks, some EV testers—such as the TIS tester—might detect it and misinterpret it as a fault. This is a common occurrence with devices that are particularly sensitive to residual voltages. To reassure any concerned installer, it is important to note that:
- All Zappi units undergo extensive testing before leaving our facility, and this behaviour is entirely safe and within normal operating conditions.
- The floating voltage poses no risk and does not indicate a fault in the Zappi unit.
For further technical insight, installers can refer to an external technical document that explains the occurrence of leakage currents in power line filters, which can help provide more background on why this floating voltage appears. The document can be accessed here: Microsoft Word - Leakage Currents in Power Line Filters (emcfastpass.com).
Addressing Concerns About Electric Shocks
If an installer raises concerns about the possibility of an electric shock, it’s important to emphasise that the current is internally limited. The amount of current that could flow through the human body if someone were to touch the system is far below the threshold needed to cause any harm. This internal limitation is a built-in safety feature, ensuring that the floating voltage does not pose any danger.