If a surge protection device is put at the main does this take care of any issues down stream. Our security guy says that his power supply to his door opperator keeps tripping out. He says that it is probable from a voltage spike. Could it be voltage spikes from the electronics of the door opperator thats causing the power supply to trip out.
Voltage spikes
- Thread starter JdoubleU
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eHunter
Senior Member
- Location
- North Texas & Georgia
The surge protector manufacturers will tell you they protect downstream.
However, if the spike generator is downstream of the protector it may be ineffective.
It is very possible that the spike is being generated by the electric door strike coil as an inductive kick when deenergized.
A simple diode, resistor and capacitor or a purchased snubber circuit should easily take care of that issue.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Also, a surge protector will have some of the characteristics of a noise filter, but will not do much if anything to noise which stays below the protection voltage of the device. As eHunter stated indirectly, it is almost always easier to prevent both noise and spikes at the source than to filter them out everywhere else.
The power supply could be shutting down from spikes on its input OR from spikes on its DC output(s) caused by devices like strike coils or solenoids that it is powering.
Sometimes the controller manufacturer assumes that inductive kick protection will be in the operator and the operator manufacturer assumes that it will be in the controller.
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eHunter
Senior Member
- Location
- North Texas & Georgia
Very true, most surge protectors are passsive and do nothing until a design threshold value has been met or exceeded.
The cure always is more effective at the source of the problem, otherwise you are simply treating a symptom and that usually requires larger more expensive measures.
[GoldDigger] "Sometimes the controller manufacturer assumes that inductive kick protection will be in the operator and the operator manufacturer assumes that it will be in the controller."
Or they are incorrectly assuming that their specified components are being used, when many times that is not the case.
There are a lot of "cheap" door strikes and solenoids that do not have integrated snubber circuitry.
Another possibility could be an defective or inferior power supply.
The cure always is more effective at the source of the problem, otherwise you are simply treating a symptom and that usually requires larger more expensive measures.
[GoldDigger] "Sometimes the controller manufacturer assumes that inductive kick protection will be in the operator and the operator manufacturer assumes that it will be in the controller."
Or they are incorrectly assuming that their specified components are being used, when many times that is not the case.
There are a lot of "cheap" door strikes and solenoids that do not have integrated snubber circuitry.
Another possibility could be an defective or inferior power supply.
How do you size the diode, resistor and capacitor or snubber circuit. Also where would you install it. I would assume on the incoming power to the unit.
ATSman
ATSman
- Location
- San Francisco Bay Area
- Occupation
- Electrical Engineer/ Electrical Testing & Controls
SPD Theory & Application
SPD Theory & Application
I think there is some valuable info on SPD's and their application in the attached discussion I had
with two PE's. The question came up after I investigated a blowup (480V) at one of the harness plugs to a controller on an ASCO automatic transfer switch. If anyone's interested in viewing the pics I think I still have them.
View attachment SPD Question.doc
Start reading from the bottom.
Tony
SPD Theory & Application
I think there is some valuable info on SPD's and their application in the attached discussion I had
with two PE's. The question came up after I investigated a blowup (480V) at one of the harness plugs to a controller on an ASCO automatic transfer switch. If anyone's interested in viewing the pics I think I still have them.
View attachment SPD Question.doc
Start reading from the bottom.
Tony
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Before you go too far with reinventing the wheel here...
If it WAS working fine, and THEN started frying power supplies, it could be that the system design has the snubber on the strike solenoid, and the resistor has burned out. That happens when people hold the button too long, like for minutes instead of seconds. It wasn't designed for that. This means that no matter how many times you replace the power supply, the strike solenoid will keep burning it out. Open up the strike coil and see if you see a little PCB with just a resistor and a cap (if it has a separate snubber board), or if there is just one board, the snubber components will be built-in and you might be able to see burned components. If so, there's your sign. Get a replacement board from the mfr because there may be collateral damage if it is not a separate snubber board. Or if not available, you can try reading the resistor color code to find a suitable replacement, that's the typical failure mode.
I did a bunch of work on casino and prison security systems, it was a constant headache. People would lean on those buttons for what seemed like an eternity and we had to buy snubber boards in bulk.
If it WAS working fine, and THEN started frying power supplies, it could be that the system design has the snubber on the strike solenoid, and the resistor has burned out. That happens when people hold the button too long, like for minutes instead of seconds. It wasn't designed for that. This means that no matter how many times you replace the power supply, the strike solenoid will keep burning it out. Open up the strike coil and see if you see a little PCB with just a resistor and a cap (if it has a separate snubber board), or if there is just one board, the snubber components will be built-in and you might be able to see burned components. If so, there's your sign. Get a replacement board from the mfr because there may be collateral damage if it is not a separate snubber board. Or if not available, you can try reading the resistor color code to find a suitable replacement, that's the typical failure mode.
I did a bunch of work on casino and prison security systems, it was a constant headache. People would lean on those buttons for what seemed like an eternity and we had to buy snubber boards in bulk.
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ATSman
ATSman
- Location
- San Francisco Bay Area
- Occupation
- Electrical Engineer/ Electrical Testing & Controls
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Sounds like a job for capacitor/diode snubbers instead of simple resistors. Although the capacitors for high current solenoids could get pretty large.
The main theoretical disadvantage of a diode is that it would slow the release of the solenoid, although not by much.
kwired
Electron manager
- Location
- NE Nebraska
Where is this prison with a casino in it?:lol:
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
No, it is a casino with holding cells.
kwired
Electron manager
- Location
- NE Nebraska
As long as you still have money in your pocket, (or these days at least a credit card that is still good) I guess they do hold some people there without any physical barriers.:happyyes:No, it is a casino with holding cells.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Why are they suspecting something electrical, it could be a mechanical problem?
A few weeks ago my overhead GDO started kicking out on overload and I found that one of the balance torsion springs had broke, or I have seen the rollers hang up on a miss aligned part of the track.
so maybe the overload is doing it's job?
Generally surge suppressors do very little in stopping transients down stream if there is a good distance from it and a load, while they will block some transients coming from the supply side, if you have something producing transients on the circuit that a load is on then good quality point of use surge devices should be used by this I mean surge devices that use more then just MOV's as its protection device.
The reason is transients are a high frequency event, and conductors can have a very high impedance to the transient source if it is closer to the load then to the panel mounted surge protector, this is one of the reasons behind why manufactures of panel mounted whole house surge protectors require us to use the shortest possible amount of wire to the panel connection, because the longer the wire the impedance climbs quickly at the high frequency of the transients, this is why both panel mounted and point of use surge protection is a must with the point of use devices with line chokes and LC circuits and or other methods having a greater ability to protect the equipment then a panel mounted unit can ever have because these methods must have the current to the load pass through the chokes and LC circuits to the load to be effective.
I posted about this in this thread "Bryant quadplex surge-suppressor outlets"
But without knowing the design of the overload system the power supply uses, I have know idea if it would be susceptible to line surges, if it is some sort of electronic overload maybe, but if it is just a thermal overload I highly doubt that line surges are the problem, even most electronic overloads would not have a problem with fast transients as my GDO overloads is electronic and with the motor and control relays right there in the same box, it would seem that this would be a problem??
A few weeks ago my overhead GDO started kicking out on overload and I found that one of the balance torsion springs had broke, or I have seen the rollers hang up on a miss aligned part of the track.
so maybe the overload is doing it's job?
Generally surge suppressors do very little in stopping transients down stream if there is a good distance from it and a load, while they will block some transients coming from the supply side, if you have something producing transients on the circuit that a load is on then good quality point of use surge devices should be used by this I mean surge devices that use more then just MOV's as its protection device.
The reason is transients are a high frequency event, and conductors can have a very high impedance to the transient source if it is closer to the load then to the panel mounted surge protector, this is one of the reasons behind why manufactures of panel mounted whole house surge protectors require us to use the shortest possible amount of wire to the panel connection, because the longer the wire the impedance climbs quickly at the high frequency of the transients, this is why both panel mounted and point of use surge protection is a must with the point of use devices with line chokes and LC circuits and or other methods having a greater ability to protect the equipment then a panel mounted unit can ever have because these methods must have the current to the load pass through the chokes and LC circuits to the load to be effective.
I posted about this in this thread "Bryant quadplex surge-suppressor outlets"
But without knowing the design of the overload system the power supply uses, I have know idea if it would be susceptible to line surges, if it is some sort of electronic overload maybe, but if it is just a thermal overload I highly doubt that line surges are the problem, even most electronic overloads would not have a problem with fast transients as my GDO overloads is electronic and with the motor and control relays right there in the same box, it would seem that this would be a problem??
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