sundance-communications.com/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Magix/ Legend Help?

Ok a customer of our are getting hit by lightning more then ever. the ground is good. They have 4 buildings on that are connected by under ground cable. The digital phones are protected by ItwLinx fuses I this it ub375 is the model number. But the 3 mlx phones are not protected. They have a magix processor and are using a legend power supply and back plain. with expainsion cabinet. well, the question is. the MLX 408 module is a lengend module and I need to know the voltage it puts out, so i can protect it. the ub375's don't work. i put them inline and the phone is dead, but they work with 4412.

Check your wiring. The 4412's only need single pair, the MLX is also digital, but uses two pair to run. They should run on the 375's, so check your wiring. Sounds like you might have something crossed.

No, everything is fine. I just need to know what the volt is on a mlx module, so i can provide the right clamping voltage.. Thanks, Eric

There are 48 volts on each digital pair. As far a the MLX mods this is two pair? I never bothered to test it until a few years back when they went digital on the Magix.

The right clamping voltage? This is low voltage and the question does not seem right. What are you trying to clamp?

The best lighting protection is one of cost and expense...

If only done right it's the best insurance.

Don't use a building ground or electricians ground unless you can't afford it.

Drive your own ground rod at each location and bond the underground shield to it. If no underground sheild a least a few spare pairs to dissipate the strike.

There is a Florida company that makes a 66 type block protector that seems to work well.


There is No such thing as a clamping voltage against the true variables of lightning. It's called grounding and protection. These devices are an offset to the customer's best insurance.

sorry like stated before I'm using ITw LInx UP3P-75 fuses on 66 blocks to protect on the 4412 digital phones, but when i use these on the MLX phones, they don't work..Meaning the MLX phone. as soon as a put the bridge clips back on the 66 block, the phone comes back to life. ItW linx says the 75V clamping on those fuses must me lower then the volts the MLX is pushing out. SO I guess what I'm asking is , What are you guys using to protect from lightning? anything? nothing? ItwLinx doesn't have the spec's for MLX phones so they don't know, and Avaya wasn't to helpful either..HELP!!

ITWlinx makes a device, Lucent called an IROB "in-range out of building protector" for the MLX sets.
Also known as a TowerMAX DS/2. Look up spec's on this or call ITWlinx.

MlX Phones uses two pair. So,you have to protect two pair.

Digital phones use one pair.

Screw the Irob. You need ground rods and true nanosecond response.. The digital 1pr phones are more suspect to lighting.

There is a bunch of ways to complete the process.

Nothing is better than a 9ft ground rod. If it's in dry sand then pee on it.

A Florida company makes a nice module unit with various nanosecond modules. Remember, Lighting strikes up and not down. I don't lie.


I don't like to talk about lightening. But I will talk about it for now. If You need a potential to ground or another electrical source or variable based on the electromagnetic elements. Think of High voltage static electricity and what direction will it flow with the least resistance.

That is when it gets hit from the ground up.

Low voltage is a culprit to this because there is not enough amps on low voltage crkts to drive or resist the high voltage or amplitude current in a natural lightening storm


It's like trying to fight lighting with a radio tower. They get hit all the time.

If you have ever seen the ground grids on radio or cell towers it might help with one's understanding of this unique energy problem.

I call it free energy for now.