R
Robospark
21[SUP]st[/SUP] Feb 2014
Today I had one of the weirdest faults I’ve ever come across. My conclusion to some may sound bizarre but from what I can see the evidence suggests it to be true. Unless of course somebody can come up with a better explanation.
I carry out electrical maintenance and installation work at a number of large distribution warehouses in northern England. The largest of which is approximately four football fields in size.
Around dinnertime today I had an urgent call from the facilities manager saying that most of the lighting in the main warehouse had failed.
On arrival, sure enough over 400 – 400watt MH high-bay fittings where out, but not all! At random intervals across some circuits the odd light was still lit.
Strangely all other equipment seems to be working fine – sockets, heaters and emergency lighting, 3P equipment etc. Only the lights where affected!
I asked one of the lads on the shop floor exactly what happened – answer, “ they flickered for about 20 seconds then went off”.This had happened over eight distribution boards and some sixty odd circuits, all at the same time. Obviously a system wide fault!
Checks back at the MCCB boards revealed no phase faults or power loss. The same was found at each section board, with not one circuit MCB triggered. I then moved on to the lighting contactors. Again, control wiring is fine with all contractors pulling in and voltage present on both sides.
Moving on the lights themselves, I checked the voltage at the connection, igniter and holder, changed and bulb; again finding nothing wrong but the light refused to strike even thought they where now stone cold and had not been lit for over an hour. If it had been a transient power outage the lights would have re-struck after 15mins but no loss of power was seen at any other equipment on any phase. The other possibility of the lights being too cold was out of the question as the temperature was about 10 degrees.
Back on the ground it was time to think. What on earth could it be and what’s so different about the MH lights to the rest of the electrical installation?
Well the only thing I could think of is that the high-bay control gear utilizes a continuous alternating magnetic field to inhibit the current flow after the lamp is lit. As many will know, once the lamp is lit it presents little resistance and becomes essentially a short circuit and requires the control gear / choke / inductor to limit the current. Was it somehow possible that the control gear had become overtly magnetised, inhibiting the current enough to stop operation?
But what could do that!
Then I remembered an article I’d read weeks ago about the effect of solar flares on electrical systems. WEB EXCLUSIVE: Potential Impact Of Solar Flares
“However, there is some evidence that some solar flares have a sudden, high intensity component to the energy that they carry. This energy could potentially mimic the effects of an EMP”.
Well as I was clutching at straws I though I’d check the space weather here; SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids and it came back with this;
“STORMY SPACE WEATHER: For the past two days, space weather around Earth has been stormy, a situation that might continue through the weekend. CMEs struck Earth's magnetic field on Feb. 19th and 20th, producing G2-class geomagnetic storms and auroras over more than half a dozen US States. Another CME is due on Feb. 21st followed by another on Feb. 22nd. The incoming CMEs are minor, but their combined impacts could add up to something more. NOAA forecasters estimate a 50% chance of polar geomagnetic storms on Feb. 21st.”
So the possibility was there that the lighting control gear had been affected and the installation is on the large side. This would also explain the apparent randomness of the fault, as nature is seldom linear.
Up to this point all power had been left on to the leave the few lights lit providing some light for operations. Was it possible that maintaining supplies where causing this state of overt magnetism too persist?
Obviously the quickest way to check was to power down the system, wait for the control gear to dissipate, the few lights to cool, and try a restart form cold. This I did and went and had a brew. Twenty minutes later, sure enough on restart all the light came back to life.
When asked by management what was the problem, I gave them my solar flare / CME explanation. The reaction to which was somewhere between do you think we are stupid and you’re a fruitcake, but unless I’m missing something it seems the most rational explanation.
So am I a fruitcake and there is a more straightforward explanation?
Or I’m I reporting a type of fault that is rarely reported.
I must say that in 30 year of doing the job I’ve not seen anything like it.
Today I had one of the weirdest faults I’ve ever come across. My conclusion to some may sound bizarre but from what I can see the evidence suggests it to be true. Unless of course somebody can come up with a better explanation.
I carry out electrical maintenance and installation work at a number of large distribution warehouses in northern England. The largest of which is approximately four football fields in size.
Around dinnertime today I had an urgent call from the facilities manager saying that most of the lighting in the main warehouse had failed.
On arrival, sure enough over 400 – 400watt MH high-bay fittings where out, but not all! At random intervals across some circuits the odd light was still lit.
Strangely all other equipment seems to be working fine – sockets, heaters and emergency lighting, 3P equipment etc. Only the lights where affected!
I asked one of the lads on the shop floor exactly what happened – answer, “ they flickered for about 20 seconds then went off”.This had happened over eight distribution boards and some sixty odd circuits, all at the same time. Obviously a system wide fault!
Checks back at the MCCB boards revealed no phase faults or power loss. The same was found at each section board, with not one circuit MCB triggered. I then moved on to the lighting contactors. Again, control wiring is fine with all contractors pulling in and voltage present on both sides.
Moving on the lights themselves, I checked the voltage at the connection, igniter and holder, changed and bulb; again finding nothing wrong but the light refused to strike even thought they where now stone cold and had not been lit for over an hour. If it had been a transient power outage the lights would have re-struck after 15mins but no loss of power was seen at any other equipment on any phase. The other possibility of the lights being too cold was out of the question as the temperature was about 10 degrees.
Back on the ground it was time to think. What on earth could it be and what’s so different about the MH lights to the rest of the electrical installation?
Well the only thing I could think of is that the high-bay control gear utilizes a continuous alternating magnetic field to inhibit the current flow after the lamp is lit. As many will know, once the lamp is lit it presents little resistance and becomes essentially a short circuit and requires the control gear / choke / inductor to limit the current. Was it somehow possible that the control gear had become overtly magnetised, inhibiting the current enough to stop operation?
But what could do that!
Then I remembered an article I’d read weeks ago about the effect of solar flares on electrical systems. WEB EXCLUSIVE: Potential Impact Of Solar Flares
“However, there is some evidence that some solar flares have a sudden, high intensity component to the energy that they carry. This energy could potentially mimic the effects of an EMP”.
Well as I was clutching at straws I though I’d check the space weather here; SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids and it came back with this;
“STORMY SPACE WEATHER: For the past two days, space weather around Earth has been stormy, a situation that might continue through the weekend. CMEs struck Earth's magnetic field on Feb. 19th and 20th, producing G2-class geomagnetic storms and auroras over more than half a dozen US States. Another CME is due on Feb. 21st followed by another on Feb. 22nd. The incoming CMEs are minor, but their combined impacts could add up to something more. NOAA forecasters estimate a 50% chance of polar geomagnetic storms on Feb. 21st.”
So the possibility was there that the lighting control gear had been affected and the installation is on the large side. This would also explain the apparent randomness of the fault, as nature is seldom linear.
Up to this point all power had been left on to the leave the few lights lit providing some light for operations. Was it possible that maintaining supplies where causing this state of overt magnetism too persist?
Obviously the quickest way to check was to power down the system, wait for the control gear to dissipate, the few lights to cool, and try a restart form cold. This I did and went and had a brew. Twenty minutes later, sure enough on restart all the light came back to life.
When asked by management what was the problem, I gave them my solar flare / CME explanation. The reaction to which was somewhere between do you think we are stupid and you’re a fruitcake, but unless I’m missing something it seems the most rational explanation.
So am I a fruitcake and there is a more straightforward explanation?
Or I’m I reporting a type of fault that is rarely reported.
I must say that in 30 year of doing the job I’ve not seen anything like it.
