X10: FD10 phase coupler/filter chematics

I have a 3 phase power system (I live in Norway) and I had three Marmitek FD10 filters installed in order to get X10 signals from one phase to another. It didn't work. My installer says that the schematics in the manual are for TN-400 V, but our system is IT-230 V (Isolated Terra System). So he says that he needs to know how to install for IT-230 V, or he needs to see some internal schematics for the FD10 so he can understand how it works and install it accordingly.

I've searched the internet for a more detailed datasheet for the FD10 or any other document which might help my installer, but found nothing with sufficient details.

Can anyone here help, or point to somewhere I might find the information that the installer asks for?


Reply to
Steinar Midtskogen
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I am not familiar with the FD10, but it may not be the right unit to use for a delta power distribution system.

Most electrical systems have "hot" and "neutral" leads. Similar X10 signals are normally superimposed on all hot leads with respect to neutral. X10 modules connected between hot and neutral receive the full signal at their locations. The only issue with this type of distribution concerns using

240V devices on a 120V distribution system. In that case, if both hot legs are driven with identical X10 signals, a 240V X10 module bridging across both legs will receive significantly less signal than a module connected from just the hot lead to neutral. Imbalances in loading may provide enough signal for the 240V X10 module to function, but there are other ways of dealing with this issue.

The delta 240V connection exhibits a similar problem. There is no neutral to use as a reference for X10 signals. Like 240V devices on a split

120V/240V service, X10 modules will receive the signal differentially off two legs. If the same signal is coupled to all 3 legs, the signal level at the receiving X10 location will depend on load imbalances to that point. So, that type of coupling system will not work very well.

The goal in a delta distribution system is to produce as strong a signal as possible between each of the legs. One phase will receive the full output of the X10 transmitter. Ideally, all X10 devices would be on that phase. If X10 devices are on all three phases, a capacitor divider can be used to the third leg. That will drive the third leg with approximately half the amplitude of the original signal. As a result, devices on the driven X10 phase receive the full output of the X10 transmitter, and devices on the other two phases will receive about half that amplitude. Two 0.1uF 240V capacitors rated for direct connection across the AC powerline can be used for this application.


Reply to
Jeff Volp

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