PQube 3 meter · Treasure Island · Live instrument log

Power Quality

Every voltage sag, swell, transient, and interruption recorded by the island's power-quality meter, published as it happens. These are real instrument readings, not estimates and not outage reports. A brief sag is logged here as a sag, never as an outage.

Latest event: Voltage Sag · Sat, Sep 26, 2026, 1:18:54 PM PDT
Deepest dip: 0.00% of nominal · Thu, Nov 23, 2023, 4:01:22 PM PST
Events logged: 16
Monitor: Watching

Why this matters

Why a public meter matters

Outage logs can't see what breaks your equipment. On September 12, 2023, this meter recorded a voltage sag to 0.03% of nominal for 1.8 seconds — deep enough to trip equipment on site. Two days later, SFPUC's official word was that there were “no outages” that day. Both statements were true: outage logs track sustained service loss, not the brief voltage collapses that destroy appliances. Without a power-quality meter, that event officially never happened.

The meter is the only precise public record. In October 2021, island residents told the Board of Supervisors about 6+ hour outages and repeated brownouts. This meter's charts confirmed their account almost exactly: a 6.6-hour outage on October 24, a 32-minute outage on October 27, and six voltage sags that month. Without the instrument, those events are anecdotes; with it, they're evidence.

It's cheap — and the city already agreed. A voltage-only PQube 3 monitor lists at $3,014; the full power analyzer at about $4,837. Five monitoring points across the island's feeders is roughly $15,000–$25,000 one time, with near-zero operating cost — the meter emails its own reports around the clock. SFPUC ordered a monitor for the main island feed in August 2023 and added one to its budget that October. The remaining step is making the data public.

If you felt a flicker or lost power, report the outage so it can be matched against the instrument record.

Voltage SagSat, Sep 26, 2026, 1:18:54 PM PDTDirect link

Event magnitude

85.22%

of nominal voltage

Duration

0.017 s (about one 60 Hz cycle)

Trigger channel: L1-N
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

A brief dip below 90% of nominal voltage on one or more phases. The power stayed on; equipment may have flickered. A sag is a brief dip, not an outage: the lights may have flickered, but power stayed on.

Oscilloscope waveform captured during the voltage sag on Sat, Sep 26, 2026, 1:18:54 PM PDT — WAVEFORM CAPTURED BY THE METER · TAP TO VIEW FULL SIZE

RMS plot and per-channel readings

RMS voltage plot for the voltage sag on Sat, Sep 26, 2026, 1:18:54 PM PDT

Min / max readings (full window and event-only)
Channel	Min	Max	Min (event)	Max (event)
N-E	0.07V	0.07V	0.07V	0.07V
L1-N	102.3V	121.6V	102.3V	112.5V
L2-N	120.3V	133.7V	127.7V	133.7V
L3-N	120.5V	122.3V	121.5V	122.3V
L1-L2	202.0V	209.1V	202.0V	205.5V
L2-L3	209.1V	209.9V	209.1V	209.5V
L3-L1	208.1V	210.1V	208.1V	209.4V
L1	Amp	11.59A	17.96A	11.59A
L2	Amp	11.73A	17.44A	12.92A
L3	Amp	7.77A	11.09A	7.77A
N	Amp	6.85A	14.07A	8.77A
L6	Amp	4.880A	5.819A	4.880A
L7	Amp	4.834A	5.774A	4.834A
L8	Amp	2.406A	3.987A	2.406A
Frequency	60.000Hz	60.020Hz	60.000Hz	60.011Hz
Power	3.429kW	3.988kW	3.429kW	3.988kW

InterruptionThu, Nov 23, 2023, 4:01:22 PM PSTDirect link

Voltage remaining

0.00%

of nominal voltage

Duration

1.96 s

Trigger channel: L1-N
Trigger threshold: 10.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

Voltage dropped to near zero: a genuine loss of power for the duration measured.

Oscilloscope waveform captured during the interruption on Thu, Nov 23, 2023, 4:01:22 PM PST — WAVEFORM CAPTURED BY THE METER · TAP TO VIEW FULL SIZE

RMS plot and per-channel readings

RMS voltage plot for the interruption on Thu, Nov 23, 2023, 4:01:22 PM PST

Min / max readings (full window and event-only)
Channel	Min	Max	Min (event)	Max (event)
N-E	0.04V	0.14V	0.04V	0.14V
L1-N	0.0V	120.0V	0.0V	60.5V
L2-N	0.0V	120.3V	0.0V	47.7V
L3-N	0.0V	120.2V	0.0V	23.0V
L1-L2	0.0V	208.2V	0.0V	99.4V
L2-L3	0.0V	212.8V	0.0V	127.4V
L3-L1	0.0V	211.7V	0.0V	117.1V
L1	Amp	0.00A	69.47A	0.00A
L2	Amp	0.00A	73.93A	0.00A
L3	Amp	0.16A	89.35A	0.16A
N	Amp	0.00A	18.63A	0.00A
L6	Amp	0.000A	58.721A	0.000A
L7	Amp	0.046A	72.411A	0.046A
L8	Amp	0.000A	75.366A	0.000A
Frequency	59.896Hz	60.017Hz	59.901Hz	59.901Hz
Power	-0.121kW	22.426kW	-0.004kW	2.804kW
Jim	Mirowski	Treasure	Island	Wines
Tasting	Room	(Est	2007)	www.tiwines.com

InterruptionSun, Sep 24, 2023, 12:42:52 PM PDTDirect link

Voltage remaining

0.00%

of nominal voltage

Duration

1.93 s

Trigger channel: Not recorded
Trigger threshold: 10.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

Voltage dropped to near zero: a genuine loss of power for the duration measured.

AlertSun, Sep 24, 2023, 12:42:51 PM PDTDirect link

Event magnitude

0.00%

of nominal voltage

Duration

2.06 s

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

AlertTue, Sep 12, 2023, 11:04:07 AM PDTDirect link

Event magnitude

0.03%

of nominal voltage

Duration

1.82 s

Trigger channel: L2-L3
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

RMS plot and per-channel readings

Min / max readings (full window and event-only)
Channel	Min	Max	Min (event)	Max (event)
N-E	0.07V	0.11V	0.07V	0.11V
L1-N	2.5V	125.5V	2.5V	125.5V
L2-N	0.1V	119.7V	0.1V	119.7V
L3-N	0.0V	123.3V	0.0V	123.3V
L1-L2	0.1V	213.7V	0.1V	213.7V
L2-L3	1.6V	207.1V	1.6V	207.1V
L3-L1	1.7V	217.6V	1.7V	217.6V
L1	16.31A	16.40A	16.31A	16.38A
L2	12.49A	12.62A	12.51A	12.62A
L3	19.93A	20.23A	19.93A	20.23A
N	10.04A	10.24A	10.04A	10.24A
L6	0.000A	0.000A	0.000A	0.000A
L7	0.000A	0.046A	0.000A	0.046A
L8	3.356A	3.723A	3.356A	3.723A
Frequency	60.022Hz	60.028Hz	60.026Hz	60.026Hz
Power	-0.189kW	5.733kW	-0.189kW	5.660kW

Voltage SagSun, Oct 31, 2021, 6:10:00 PM PDTDirect link

Event magnitude

83.01%

of nominal voltage

Duration

0.033 s (about one 60 Hz cycle)

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

Voltage SagSun, Oct 31, 2021, 6:47:27 AM PDTDirect link

Event magnitude

74.48%

of nominal voltage

Duration

0.042 s (about one 60 Hz cycle)

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

InterruptionWed, Oct 27, 2021, 7:02:45 AM PDTDirect link

Voltage remaining

0.00%

of nominal voltage

Duration

32.0 min

Trigger channel: Not recorded
Trigger threshold: 10.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

Voltage dropped to near zero: a genuine loss of power for the duration measured.

AlertWed, Oct 27, 2021, 7:02:45 AM PDTDirect link

Event magnitude

0.00%

of nominal voltage

Duration

32.0 min

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

AlertWed, Oct 27, 2021, 2:07:07 AM PDTDirect link

Event magnitude

69.82%

of nominal voltage

Duration

0.050 s

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

InterruptionSun, Oct 24, 2021, 8:23:19 PM PDTDirect link

Voltage remaining

0.00%

of nominal voltage

Duration

393.8 min

Trigger channel: Not recorded
Trigger threshold: 10.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

Voltage dropped to near zero: a genuine loss of power for the duration measured.

AlertSun, Oct 24, 2021, 8:23:19 PM PDTDirect link

Event magnitude

0.00%

of nominal voltage

Duration

393.8 min

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

AlertSun, Oct 24, 2021, 11:54:57 AM PDTDirect link

Event magnitude

41.94%

of nominal voltage

Duration

0.042 s (about one 60 Hz cycle)

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

AlertWed, Oct 20, 2021, 6:47:52 PM PDTDirect link

Event magnitude

60.98%

of nominal voltage

Duration

0.083 s

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

AlertTue, Oct 5, 2021, 7:39:07 AM PDTDirect link

Event magnitude

57.85%

of nominal voltage

Duration

0.092 s

Trigger channel: Not recorded
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

AlertSat, Jun 12, 2021, 2:57:47 PM PDTDirect link

Event magnitude

0.00%

of nominal voltage

Duration

4.77 s

Trigger channel: L1-N
Trigger threshold: 90.0% of nominal
Nominal: 120 / 208 V
Meter: P3001520

RMS plot and per-channel readings

Min / max readings (full window and event-only)
Channel	Min	Max	Min (event)	Max (event)
N-E	0.07V	34.53V	0.07V	34.53V
L1-N	0.0V	123.8V	0.0V	123.8V
L2-N	0.0V	119.1V	0.0V	118.0V
L3-N	0.0V	119.2V	0.0V	119.0V
L1-L2	0.0V	207.0V	0.0V	205.9V
L2-L3	0.0V	206.6V	0.0V	205.4V
L3-L1	0.0V	207.8V	0.0V	207.3V
L1	11.46A	11.66A	11.48A	11.62A
L2	10.42A	10.56A	10.45A	10.56A
L3	18.90A	19.04A	18.92A	19.02A
N	12.90A	13.13A	12.92A	13.08A
L6	0.09A	0.14A	N/A	N/A
L7	0.09A	0.11A	N/A	N/A
L8	0.09A	0.14A	N/A	N/A
Frequency	0.000Hz	59.997Hz	59.994Hz	59.996Hz
Power	0.000kW	4.737kW	0.000kW	4.704kW

How this log works

A Powerside PQube 3 power-quality meter (serial P3001520) installed at Treasure Island Wines monitors the island's 208 V three-phase service around the clock. When voltage moves outside its configured thresholds, the meter emails an event report with oscilloscope waveforms, and this page publishes it automatically.

Event categories are kept separate on purpose. A voltage sag is a dip that the lights ride through; an interruption means voltage fell to near zero. Conflating the two would inflate outage counts, so this log never does.

The meter is operated by Treasure Island Wines, which forwarded its event alerts to this project for publication as a public power-quality record. If you felt a flicker or lost power, report the outage so it can be matched against the instrument record.