modulator

[Robert Gift]

Would be nice to have actual statistics of what happens in real life.

Though thexponentil horns are non conductive, lighting can still enter and go righto the voice coil andamage begins from there on down.

If lightning strikes a motor, the motor housing will likely conducthe current around the internal motor coils, etc., to ground.

Motors are big brutes, not sensitivelectroncircuits.

They can withstand lots of electrical abuse.

I assume both sirens arengineered for good lightning survival.
But if both be identically protected/grounded, I expecthe motor to survive
the same bolt which would kill an electronic siren.

[StonedChipmunk]

I'm going to cast my vote for the electromechanical surviving (without taking in to account all that Whelen marketing B.S.) because the electronics in an electronical siren are MUCH, MUCH, MUCH more sensitive to lightning than metal parts. My point is, if an electromechanical siren is hit by lightning then chances are you can replace the parts and you are good to go. But, if an electronic siren is hit, the board is fried and the siren will never work again unless you get all new parts, which is essentially getting a do-it-yourself siren. Electromechanical sirens, though, only have to worry about the electronics in the decoder and such, which can be replaced as it is not the base of the siren. Of course, some parts may be fried and the motor might not work, but chances are it is more likely to be cheaper to replace and will survive more than an electronic siren.

[jkvernon]

The Franklin County EMA guy said that lightning strikes affect the Whelen sirens more than the old TBolt sirens. He pointed out that they spent thousands last year on internal components damaged on the Whelens from lightning (drivers, amplifiers, ect..). Not to say that they aren't suseptable to lightning, but it does much less damage and saves money.

[Robert Gift]

Sorry about the lightning damage.
Thoughthey had a good handle in minimizing such damage.

The nature of being a siren puts you in harms way.
Maybe they should place sirens within high-tension power towers.

Perhaps it would be good to encase an electronic siren speaker array
in a grounded "Faraday cage" to ty to prevent such damage.
The solar panels would also need to benclosed.

Sinceverything else is in metal conduit and enclosed in metal cabinets,
it should be well protected.

The lucky thing about many motors is thathey are often inside heavy metal cases and frames, which conducts high voltages/amperagesafely
around the internal coils.

But lightning can still appear to disobey "our" laws of physics and do strange unexpected things andefeat our safety measures.

Robert the -IXX Last smited by #43
(Do we have -XX?)

[SirenMadness]

The chance of anything getting struck by lightning depends upon its charge in relation to the sky, plus its surface area. A larger surface area makes its chance of getting hit much bigger, because it eases the resistance factor. Speaking of resistance, the Ohm factor of the entity decreases its chance of getting struck.
But, yeah, internal components within a fully enclosed conductive shroud are protected from lightning.

[Elliott]

The Franklin County EMA guy said that lightning strikes affect the Whelen sirens more than the old TBolt sirens. He pointed out that they spent thousands last year on internal components damaged on the Whelens from lightning (drivers, amplifiers, ect..). Not to say that they aren't suseptable to lightning, but it does much less damage and saves money.

So in other words, Whelen doesnt exactly "rule"? Oh well, this was a MODULATOR thread anyway.

[loudmouth]

fiberglass or not if its got water on it it will conduclt electricity.
we had a saftey class just about the dangers of using a wood pole saw around a electric wires or being up in a tree near electric wires. they said the out side of the of the pole is dry the iner core can still have mosture and would be able to conduct electricty the same with the tree but the tree has the Xylem and phloem transporting water and the tree can become conductive.
the same with asiren the out side becomes wet from rain the lighting hits the the siren and Zap the siren could be fried.

[Whelen Rules]

I think it has a lot to do with how well you protect them. We have had our Whelen vortex sirens for 7 1/2 years and never had one struck by lightning and we use them for tornado warnings. We have all kinds of weather here in Middle Tennessee ie: tornadoes, hail, highwinds, winterweather and lots of lightning. We have had a case of high winds damaging the oscillator on one siren before but that was in a downburst with a severe storm. I agree if its wet its going to conduct electricity. Its like Whelen says "Any siren sitting in a open area is proned to lightning strike" wether it be electronic or electromechanical they a both have the same chance to get struck. The electronics may suffer more damage though... Now lets get back on topic of the Modulator please.
Why did Fedsignal raise the pitch of mods even higher and what made them go to dual tone sound? I think the older model single tone Mods sound a lot better.

[SirenMadness]

The Modulator has such a high pitch so that the drivers inside do not have such a large profile of vibration. That way, they would get worn later than drivers of a lower-frequency production.
But it is still nice to know that the Modulator has a very broad wind-down.

[Whelen Rules]

But Whelens use low tones 465 when in alert and the whelen speakers last about 20-30 years before blowing out, could it be Whelens speakers are designed differently? Also Whelens use 400 watt drivers where as Mods use 4 100 watt drivers per cell.