Concept
Galvanic isolation
- ID
concept:galvanic-isolation- IRI
https://solarlattice.org/kb/concept/galvanic-isolation- Status
- active
- Also known as
- transformer isolation, galvanically isolated
- Category
- Inverters
- Concept kind
- electrical
Galvanic isolation means two parts of a circuit have no conductive connection to each other. In inverters a transformer usually provides this isolation, and spec sheets may give the isolation method as Transformer. A transformerless inverter has no isolation transformer between its DC and AC sides, so it has no galvanic isolation. With these inverters, the PV circuits must stay isolated from ground and only the module mounting frames may be grounded. If a grounded PV array is connected to a non-isolated inverter, the inverter shows an insulation error or logs an event. Non-isolated inverters also limit how much PV array capacitance to ground they accept; one SMA manual gives a coupling capacity limit of 12.6 μF. Meters and sensors also use galvanic isolation on their signal ports, for example isolation up to 1000 V between supply and RS485, or inputs and outputs isolated to 2500 volts.
<!-- review notes
- sentence 2: support check: partial - Isolation method Transformer is shown, but 'usually' provides isolation in inverters is only implied, not stated.
- sentence 7: support check: partial - Both isolation figures appear, but the passages don't say these are meters or sensors; the 2500 V item isn't tied to a device type.
- sentence 7: review: partial - Both isolation figures (1000 V between supply and RS485, and 2500 V for all inputs and outputs) are quoted, but the passages never say these are meters and sensors or call them signal ports.
-->
Claims
related_to
c1 drafted · lead
Transformerless inverter topology
Scope: products Delta M36U/M42U three-phase string inverter proposed, Delta M60U/M80U three-phase string inverter proposed, Sunny Tripower TL-US, Sunny Tripower CORE1-US, Sunny Highpower PEAK3, Sunny Tripower X (international)
Inverters with no transformer have no galvanic isolation between the DC and AC sides.
c2 drafted · lead
Inverter transformer
A transformer is the isolation method in isolated designs; transformerless designs lack an isolation transformer between AC and DC sides.
c3 drafted · lead
Isolation transformer proposed
Scope: products Delta M36U/M42U three-phase string inverter proposed, Delta M60U/M80U three-phase string inverter proposed
The units name the isolation transformer as the element that is absent in transformerless inverters.
c4 drafted · lead
Ungrounded PV array
Scope: products Delta M36U/M42U three-phase string inverter proposed, Delta M60U/M80U three-phase string inverter proposed
Without galvanic isolation, the connected PV circuits must be kept isolated from ground; neither side of the array may be bonded to ground.
c5 verified · fact
Grounded PV array
Scope: products Delta M36U/M42U three-phase string inverter proposed, Delta M60U/M80U three-phase string inverter proposed, Sunny Tripower TL-US, Sunny Tripower CORE1-US, Sunny Highpower PEAK3
Grounded PV modules must not be operated with non-isolated inverters; connecting them raises an insulation error or event. Only the module mounting frames are to be grounded.
verified by: review-workflowverified on: 2026-10-24
c6 drafted · lead
RS-485
Example of galvanic isolation between a sensor supply voltage and its RS485 interface.
Referenced by
Data