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Sterling Power Galvanic Isolator/Zinc Saver

5 July 2017  |  Mike


Sterling Power are leaders in marine power solutions; here we take a look at what their ProSave galvanic isolator does, why you need one fitted to your boat and which model you'll need.

What is a Galvanic Isolator?

Boats are normally fitted with Zinc (in seawater) or Magnesium (in fresh water) anodes, below the waterline to act as a sacrificial piece of metal that essentially corrodes in preference to your expensive propellers and stern gear.

The metal under the water, such as a propeller, acts like a battery element. Using the seawater as an electrolyte it creates a circuit and electricity is generated. This action speeds up the destruction of your propeller.

If the boat is fitted with Zinc anodes, they will be eaten away in preference to your propellers, as the metal is more reactive. This is fine, and as long as you keep fitting new anodes every year or so, the metal stern gear will be protected.

Why do I need a Galvanic Isolator?

If you fit new anodes every year, in theory everything should be fine. Unfortunately your neighbour may not be so particular about preventative maintenance.

If you have your boat connected to shore power in a marina, and so does your neighbour, you have just bonded his boat to yours. Better still, you may also be bonded to the lovely steelwork of the marina.

Now your anodes are sharing the sacrificial load of all the other boats and earthed metalwork in the marina! So the Galvanic Isolator will allow you to retain the earth bond for safety, without having to share your anodes with your neighbours and the marina at large.

Which Galvanic Isolator do I need?

You need to buy the right model for the shore power rating. We stock the 16A and 30A models, and a 50A model is available to order.

Sterling Power ProSave ZS16A 16A Galvanic Isolator £71.95

Sterling Power ProSave ZS30A 30A Galvanic Isolator £91.95

How easy is it to install?

This isolator can be fitted in 15 minutes:

  • Unplug the shore power!
  • First read the installation manual
  • Mount the unit near the rear of the shore power socket
  • Cut the earth lead to the socket in half and join to the isolator terminals

No more sharing your anodes with other marina users.