Why does the 4050 80 no longer meet building codes?

What’s the reason why the old 4050-80s no long meet building codes? Just was ceroius is to why. Also I got 2 4050-80s!!! :smiley: and a 4051 off Ebay!

System test now that I have everything I was waiting for will be between may 20th-last day of the month! Stay tuned system is had major changes to my Simplex 4100Us and my Simplex 4100ES FUI with the EPS+ power supply plus new panels and new devices all panels are now linked together!

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The Americans with Disabilities Act of 1990, and NFPA 72 (the National Fire Alarm Code) both set certain light coverage requirements on visual fire alarm signals. They also must have a certain flash rate (between 1 and 2 Hz), a certain flash duration (now .02 seconds), and must produce a white flash (as opposed to red or incandescent yellow).

The 4050-80 isn’t bright enough, nor does it flash at the correct rate. And it produces red light.

Also, be careful when using incandescent lights on newer panels. I heard that there was a chance that they could fry the NAC.

Don’t forget to make sure the lamp is polarized before hooking it up to the NAC.

I am wondering what made them decide to upgrade the codes at that point? Is it something they take a look at every few years or was there something else?

It was because the ADA was passed. It was a federal law and thus the NFPA, not being a government organization itself (while they set codes they are not affiliated with the Federal government nor a government agency), had to comply with it just as everyone else did.

Thus, the law made the existing codes null and void as they did not comply with the new law which dictated these requirements for fire alarms and other signaling devices, except for existing buildings which were grandfathered in and didn’t need to meet ADA compliance unless they were renovated or added onto and the fire alarm system was upgraded or the existing fire alarm system broke and needed replacement, then those buildings would be then required to meet the Federal requirement.

Why did they decide to pass it then? Was it in the works for a while?

Thanks for the info guys! Another question, if I have black and white wires and the unit is 24VDC

Does this mean my light plate is polarized? What do I do to make it polarized? Also I’ve never worked with a 4050-80 and the wires, does black mean positive and white means negative like wiring in a house or does back mean negative and white mean positive following the method of for DC positive is red (white) than negitive (black). Any info would be great! Also does the panel protect the NAC from operating and throw a trouble if it’s reversed wired like the current notification appliences? Am I safe using it with a 4005?


A few quick tests with a meter will decide for sure. My faded memory of these unite are that they are not polarized. The early units were used in a time when visual signals were optional and not required to be supervised. I installed many that were operated by a march time relay. In later years the units came with a diode harness attached to the plate with a wire tie but not wired to the socket. If the installation required supervision the installer was instructed to wire the diode in series with the lamp socket. I think the diode harness came with a red and white wire connected. The white wire from the socket was connected to the white wire from the diode. That left a red and black wire to connect to the NAC.

To be sure, an ohmmeter connected to the wires will decide the question. Be sure the light bulb is good. If there is no reading either way the bulb is bad or it is polarized and the meter cannot read through the diode. After being sure the bulb is good, switch the meter to the diode check setting. It should show conductance in one direction and no conductance when the connection is reversed.

Incandescent light bulb filaments of any voltage or wattage have much lower resistance cold so they have a turn on surge. Once the filament is hot the resistance decreases. One or two of these probably will not have an effect on a 4005 NAC.

Interesting; at my first elementary school, apparently while the Simplex 4208 system had DC signal output with 4051 horns, the 4050-80 light plates apparently used 120 VAC, or at least the bulbs they typically used in the early 70s. And yes, I was told when the school was originally built the horns sounded on Continuous while the lights flashed on and off via a coding wheel in the 4208 (I’ve seen quite a few 70s Simplex systems configured that way.) Then in the 80s when they tied a Simplex 2001 or 4002 panel into the 4208 for added-on duct detectors, they changed the coding so the horns and lights both operated on slow (like 20bpm) March Time.

But yes, the 4050-80 light plates are definitely no longer ADA-compliant. This is why they’ve replaced them at my college in the buildings that originally had them (the ones built in 1978, as the 1971-1972 buildings originally used Standard Electric Time systems) had numerous upgrades to make the facilities more ADA-compliant; not just the fire alarm systems, but the door handles and the automatic doors for handicapped people, braille room number signs, drinking fountains, you name it. They first started replacing the Simplex 4051+4050-80s with Space Age VA4 horn/strobes (amazingly, in the Administration building, two of the 4051s were preserved but re-mounted on Faraday 2701-K strobe plates to make them ADA-compliant!) Then when they redid the fire alarm systems in three of the buildings, all the previous alarms, not just any remaining old Simplex alarms but the Space Age VA4s as well, got replaced with System Sensor SpectrAlert Advance horn/strobes, just like at my first elementary school. But in that school’s case, their old Simplex system was failing, so they HAD to replace it, but all they replaced were the panels and the alarm signals. They still have the existing pull stations intact (mostly break-glass 4251-30s), the added-on Simplex duct detectors and even the old heat sensors. (You’d think in places like the classroom pods or the offices or electrical/mechanical rooms that still have old heat sensors they’d replace them with newer smoke detectors.)

A 4208 with 120 VAC flashing lights was typical for the time. That was especially true for the 4208AX systems using series AC horns operated by “H” modules. The 4050 light plates came in several variations as shown below. If the flasher motor in the panel gave up we would install the flasher board from the 4050-84 to drive the relay. That was in the days when we could order about every piece and part used in producing a product.

The ADA of 1990 was a huge sweeping bill that sought to prohibit discrimination of Americans with disabilities. It not only addressed accessibility of buildings, but also things like access to employment, public transportation, service animals in public places, etc. It can take many years of research and drafting before a bill this large gets passed. A lot of the research is done by interest groups that work alongside members of Congress. When a bill gains enough support that it is likely to pass, groups will usually try to “go big or go home” with lobbying for additional items while they have the opportunity. New visual signal requirements was probably lobbied for by an interest group advocating on behalf of Americans with hearing impairments.

OK but now I have to ask because I am curious how long did they work on the bill before presenting it. Just wanna get a feel for how long this would have taken.

Cool! That’s very interesting that the had a 4208AX! But where would I get a diode and what would I get what’s the name ohms volts reseistense etc.? also my bulb is burned out. Where would I get a 24VDC bulb? i think it’s a screw in type. It’s defenatly a 24VDC unit thus the model number a 4050-80. Any info on the diode and a picture of a wiring diagram would be greatly appreciated! As I’ve said I’ve never dealer with this type of light plate.


The excerpt below is from:

<LINK_TEXT text=“Americans - Wikipedia … ct_of_1990”>Americans with Disabilities Act of 1990 - Wikipedia</LINK_TEXT>

The ADA has roots in Section 504 of the Rehabilitation Act of 1973.


The idea of federal legislation enhancing and extending civil rights legislation to millions of Americans with disabilities gained bipartisan support in late 1988 and early 1989. In early 1989 both Congress and the newly-inaugurated Bush White House worked separately, then jointly, to write legislation capable of expanding civil rights without imposing undue harm or costs on those already in compliance with existing rules and laws.


Over the years, key activists and advocates played an important role in lobbying Members of the U.S. Congress to develop and pass the ADA, including Justin Whitlock Dart, Jr., Patrisha Wright and others.

Ms. Wright is known as “the General” for her work in coordinating the campaign to enact the ADA. She is widely considered the main force behind the campaign lobbying for the ADA.

Is the 4050-80 like this? (later version)

If it is, then it takes the same flashlight-style bulb as the Simplex 2903 light plates and the Space Age AV32 light plates. RadioShack sold them, but too bad they’re going out of business…

Diodes can be purchased at Radio Shack (if there are any remaining near you), Ebay (search for 1N4004 diode), or Amazon (same search). The 24 volt units used a miniature bayonet base bulb. An 1829, I think. The 120 volt types used a 145 volt 6 watt S6 bulb with a screw type candelabra size base. You can search the internet for the bulbs. Lots of places have them.

I don’t have any of the type bulbs mentioned above. A standard 75 watt light bulb measured around 14 ohms.

What is the cathode end? Also does that only go on the positive end or negitive end in series or parallel where both the field wiring and the lap wiring and the diode wiring all come together in a total of 3 wires connected to a wire nut?

Does the cathode end go on the light plate wire side or the field wiring side?

This should explain everything.

Fantastic! That helped really helped.