Steve,
Just read your recent message, regarding the Lighting issues.
I will quote parts of the message with my comments.
Went to check my job today. I think at this point it is obvious what the problem is. (32) (2x4) 2 tube (2x4) lay in fixtures on 1 circuit, not counting 13 exit lights on same circuit, all pulling constant load. Another 7 outside emergency lights that only come on with the exit light battery when power is off. Total amps on circuit is 19 amps, on a 20 amp breaker.
As
Tesla said above, the Circuit should be Rectified, as the Load is > 15.999 Amps, and running _Continuously_ for more than 179 Minutes, 59 Seconds.
Unless the Conductors are all #10's, this is an issue.
Poor Design and Installation is the culprit.
The 2x4 2 Lamp Fixtures would draw 64 VA each (0.534 Amps @120V). Thirty-Two Fixtures equals 2,048 VA - or 17.067 Amps @ 120V.
The Exit Signs (if they are LEDs), would draw 5 VA each, for a total of 65 VA for all 13 Exit Signs.
65 VA @ 120V = 0.54 Amps.
Base total for the single Lighting Circuit so far: 2,113 VA, or 17.61 Amps @ 120V.
Loads for the Charging functions on the Exits and the Em. Ballasts:
a: Exit Signs: 2 VA each - total of 26 VA (0.22 Amps @ 120V),
b: Emergency Ballasts: 12 VA each; total of 156 VA (1.3 Amps @ 120V).
Total of 183 VA (1.52 Amps @ 120V).
Add the Charging Loads to the Lighting Loads:
2,113 VA Lighting + 183 VA Charging = 2296 VA (19.134 Amps @ 120V)
If the Lighting was connected to a 277V 20 Amp Branch Circuit, Thirty-Two Fixtures on the same Circuit would not be a problem (I wonder if that was the original idea...)
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Total sq. ft. of building is 13,254 sq. ft.
Is the Building's Service Voltage only 208Y/120V 3 Phase 4 Wire? Seems the Footprint Area of +13K Sq. Feet would have 480Y/277V 3 Phase 4 Wire Service Voltage.
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All lights are controlled from 8 locations. The light furthest away from the electrical panel is operating on 95.3 volts. The light I actually started working on, (on the original trip) was working at 90 volts(actually looks closer to electrical panel, but who knows how the conduit is run). From one end of the hallway to the other is 184 ft. (by the scale on prints), not counting the hallways that branch off to the front and back of building at the different entrances.
It appears the Lighting Circuit runs through (2) 3-Way Switch "End Points", and (6) 4-Way Switch "Mid Points", then to the First Fixture near that last 3-Way Switch location.
If the end of the Switch Loop is at the end of the Hallway (184 Feet), the Voltage Drop at that point would be 11.51%; which would yield 106V (figuring #12 Conductors).
This is just the Switch Loop, not including the Home Run Length.
Figuring an additional 100 Feet for the Home Run (total Circuit Length from Panelboard to last 3-Way Switch = 284 Feet), the Voltage Drop becomes 17.76%.
17.76% loss from 120V = 98.69V.
The Fixture which readout at 95.3V is probably closer to the Panelboard - per total Circuit Length, than the Fixture showing 90V.
At these lengths, the Circuitry should have been at least #10's, with (2) Circuits coming in to the "Middle" of the Hallway.
Occupancy Sensors would have been a better choice for this Corridor's Lighting Controls.
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As far I can tell now, all the lights are left on 365 days of the year. There are no emergency lights that stay on when the hall switches are turned off. The emergency lamps only come on when the power to the circuit goes off. Out of 13 emergency lights (2x4 lay-ins) shown on the prints, only 8 are working. Probably the reason they leave the lights on all the time, is for security reasons. Looks like the architect would have designed for some lights to stay on constantly.
I agree - there should be a few Unswitched Fixtures in this Corridor for Egress purposes (Emergency Egress without complete Outage, and Non-Emergency Egress).
The Non-Functioning Emergency Fixtures may have failed due to Heat + Voltage Drop.
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I looked at the wiring diagram for the emergency ballast, thinking that the brown leads may need to be connected for this purpose, but not so according to the Notes they include.
Is this information from the Dual-Lite UFO-3AW Schematic?
I only see (1) Brown Lead, which connects to the "Charging Indicator" Lamp (Lamp Loop = Brown + Violet).
If you have a different Schematic / Ballast type, please let me know.
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Voltage on the Unswitched feed is 120 volts.
Voltage on the switched feed, (which controls all the lights) ranges from 90 volts to 95 volts.
It appears the Unswitched Lead is from the beginning of the Switch Loop (at the Home Run location), and since there is less than 240 VA (2 Amps @ 120V) Load on this segment, the Volt Loss is dramatically less.
This slightly changes my Voltage Drop Calculation, as the Load at the end of the Switch Loop is 1.52 Amps less.
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P.S. One more question: Wondering why the emergency ballast I originally checked was causing the regular ballast not to work in the fixture, yet the other lights in the hallway that have bad emergency ballast, are still working??
Good question!
The Ballast you worked on may have been setup to drive the Lamps only when there is an Outage, or the Voltage on the Switched Circuit was below the Threshold for Ballast Operation.
If the Failed Ballasts were connected, so as to drive the Lamps only during an Outage, the Failure of the Ballasts would probably exclude them from the Circuit... I am not too sure, though.
Chances are these Fixtures will have several "Variations" in how they were Connected (i.e. Whom ever got the exciting task of installing the Em. Ballasts, made up some Fixtures as Switchable, and others as Normally Unlit... possibly due to a "Liquid Lunch" experience).
-- Scott