I noticed a loud humming, if the input of an isolation transformator is supplied by a power station (like a EcoFLow Delta 3 max Plus). In particular there is a transporter equipped with an isolation transformator, to power 230V devices in the car and supply the 12V battery charger. Connected to the grid, the transformator is very silent, but connected to a power station it gets very noisy.
Any idea what that could cause? and what can be done to mitigate this? will it harm the transformator?
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
4
It’s most likely caused by a distorted waveform coming from the Ecoflow. I don’t have an Ecoflow to test in my shop, but I do have a small Bluetti 70S and an Anker Solix F3000. You have inspired me to put an oscilloscope on them to see how dirty their outputs are compared to a high-quality inverter such as Victron. Can you or someone you know put your Delta on a 'scope and check its output?
I’m not knocking these products from Anker, Bluetti, Ecoflow, etc. as they do have their uses, but there are reasons why they are less expensive. I’ve had all three of those companies approach me multiple times to sell and install their whole-home products and I have declined each time.
I suspected something with harmonics, but I’m not skilled enough to evaluate this. I had issues with GoalZero power stations years ago. The inverters can’t provide enough power to power TV and internet router, if the fridge starts up… Victron inverters handles this situations very well.
Do you know, whether it is possible to add a filter to the power cable, to filter the harmonics?
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
6
Possible, yes, if it’s just noise and harmonics. Frequency variation, not really. In any event, the cost of polishing that turd probably isn’t worth it, in my humble opinion.
I know about the quality of the Blue manufacturer I use their products with my balcony island PV system. Unfortunately they don’t have a portable all in one system (PV charger controller battery, inverter, controller) and they are hard to reach. Couldn’t find a contact form or mail address on their website. they only state “ask your supplier”. I only wanna know if this humming is harmful for the isolation transformator.
Maybe it’s an idea to build a second connector and use it with a changeover switch. One connector to use the grid and one to connect power stations. Strictly separated with the switch.
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
10
It’s probably not going to harm the transformer, but I can’t tell you for certain. And yes, Victron does not sell to the public, nor do they provide support to the public unless the responsible distributor really screws up. Do you not have a Victron dealer or installer near you?
I use their products with my balcony island PV system. Unfortunately they don’t have a portable all in one system (PV charger controller battery, inverter, controller) and they are hard to reach. Couldn’t find a contact form or mail address on their website. they only state “ask your supplier”. I only wanna know if this humming is harmful for the isolation transformator.