Forum readers, from time-to-time I have posted suggestions that power conditioners should be strongly considered in power abatement problems.
You may find the following somewhat humorous (in a dark way). When people call with problems and claim that their equipment was "struck by lightning" we always ask how their phone and security systems are functioning. In many ways, the security systems are among the more vulnerable and the patterns of failure can help identify surge paths and magnitudes.
Frequency drift is improbable in the USA grid. Drift normally less than +/- 0.5 Hz. Very well controlled nationally. Also, if frequency drift presents a problem, use a double conversion (on-line) topology.
Since ground is but a system reference point (as well as safety) the power conditioners will keep the ref point relatively constant. Then the only other variable is the coax shield ground variation between his home and the cameras. There a person will need signal optical coupling for greatest assurance with the ground shield connected in similar fashion. If the earth as a ground has poor conductivity, it’s really difficult to change that.
The most accurate and the most time consuming method of ground testing is the fall in potential method and no testing of any kind should be conducted within 72 hours of meaningful rainfall.
Before we start to discuss grounding, we should begin with the basics. In what part of the world are you located?
Who supplies your electrical service and to your knowledge how is that power generated?
What is the condition of your electrical grounding system and is it tested periodically?
Have you recently opened your circuit breaker box and tightened the neutrals for all your circuits? As a subset, did you find any of them loose and if so how many were loose?
Do you have circuits broken down into technical loads separated from general purpose loads? Do your computers, CCTV monitors and cameras and other sensitive electronic components separated from other non-technical loads such as sewing machine and other manufacturing machines?
Do any of sensitive loads share the same circuit with high draw items such as stamping equipment, refrigerators and water coolers?
What type of electrical switches and receptacles are used within your facility, industrial, commercial or residential?
I believe a person needs to start a gradual replacement of all residential switches and receptacles with at least high end commercial ones. Herb Goldstein suggested I do for my own home. If wiring techniques were the use of quick wire installation methods, you can bet you will have over time unacceptable electrical noise levels caused by the gradual weakening of the small amount of conductor material holding the quick wire in place. I experienced noise levels that were off the chart. I replaced all of them and noise and trash levels dropped substantially. I know binding post wiring is a pain, but you soon see the results. I never had a device warm to the touch after that.
At the El Paso Federal Courthouse, Herb’s folks found grounding rods almost totally corroded and had to be replaced before anything worked properly especially the CCTV cameras. Even after grounding was corrected, common and normal noise levels were staggering and power conditioners had to be placed ahead of each of the 75 cameras in the court’s system.
I believe many electrical problems could be rectified by some good quality low impedance transformer based power conditioners for the camera power and coaxial. But just constitutes a good power conditioner?
1) Your desire is to obtain a low impedance power conditioner which consists of an input protective network, a unique isolation transformer and an output filter assembly.
2) The main purpose of the transformer is to allow the bonding of neutral and ground conductors on the output side of the transformer. This effectively eliminates common mode noise allowing the ground reference to be reestablished.
3) The transformer also provides excellent noise rejection between line and neutral. The output filter assembly ties line and neutral together at high frequencies. This assures that all remaining noise is eliminated or attenuated to a safe level, yet passes the harmless lower frequencies necessary for efficient power transfer.
4) The power conditioner must not have any bypass feature or features for any reason. Bypass allows raw unfiltered electricity to enter your electronics, thus damaging or destroying it. That would defeat the basic reason you purchased the conditioner in the first place.
These then are the basic Electrical/Electronic/Communications/Operating Power Requirements of the conditioner. These then are the testing parameters you look for: It must be assumed the facility electrical system may not have been installed or maintained in accordance with the National Electrical Code® (NEC®) or local electrical codes. The unit shall be built to Underwriters Laboratories® (UL®) standards and will conform to the general requirements of American National Standards Institute® (ANSI®) and the institute of Electrical and Electronics Engineers® (IEEE®) as specified by UL® 991. Electronic protection devices must be built-into the unit. If not provided as a standard feature, add-on devices shall be built-in and become an integral part of the unit. The conditions of passing the UL® 991 test requirements shall be that the unit must remain fully operational without any operator adjustment during or after being subjected to any or all of the UL® 991 tests as specified and modified as indicated below:
a) Overvoltage and undervoltage tests, Section 10, UL® 991.
b) Power supply interruption test, Section 11, UL® 991. Modification: Interruption time need not exceed 100 milliseconds (ms).
c) Transient overvoltage test, Section 12, UL® 991. Note: Voltage and current levels will be as prescribed by paragraph 12.8. Commercially available surge generators can be substituted for test circuits shown in Figures 12.3 and 12.4.
d) Ramp voltage tests, Section 13, UL® 991.
e) Electromagnetic susceptibility tests, Section 14, UL® 991. Modification: Commercially available fast transient (noise) generators that produce equivalent noise, amplitude and frequency characteristics as defined in paragraph 14.4 and shown in Figure 14.3, may be substituted for this test.
f) Radiated electromagnetic interference (EMI) test, Section 14.8, UL® 991. Hand-held radios, cellular phones and like emitters shall not interfere with detector operation.
g) Electrostatic discharge (ESD) test, Sections 15.1.2 to 15.3.3, only. Static discharge from any source shall not interfere with unit operation.
h) The unit shall be immune to the effects of high frequency noise, 3 to 30 megahertz (MHZ); shall be immune to normal mode noise above 10 volts and immune to common mode noise above 0.5 (½) volt.
Enjoy the day,
Bill
You may find the following somewhat humorous (in a dark way). When people call with problems and claim that their equipment was "struck by lightning" we always ask how their phone and security systems are functioning. In many ways, the security systems are among the more vulnerable and the patterns of failure can help identify surge paths and magnitudes.
Frequency drift is improbable in the USA grid. Drift normally less than +/- 0.5 Hz. Very well controlled nationally. Also, if frequency drift presents a problem, use a double conversion (on-line) topology.
Since ground is but a system reference point (as well as safety) the power conditioners will keep the ref point relatively constant. Then the only other variable is the coax shield ground variation between his home and the cameras. There a person will need signal optical coupling for greatest assurance with the ground shield connected in similar fashion. If the earth as a ground has poor conductivity, it’s really difficult to change that.
The most accurate and the most time consuming method of ground testing is the fall in potential method and no testing of any kind should be conducted within 72 hours of meaningful rainfall.
Before we start to discuss grounding, we should begin with the basics. In what part of the world are you located?
Who supplies your electrical service and to your knowledge how is that power generated?
What is the condition of your electrical grounding system and is it tested periodically?
Have you recently opened your circuit breaker box and tightened the neutrals for all your circuits? As a subset, did you find any of them loose and if so how many were loose?
Do you have circuits broken down into technical loads separated from general purpose loads? Do your computers, CCTV monitors and cameras and other sensitive electronic components separated from other non-technical loads such as sewing machine and other manufacturing machines?
Do any of sensitive loads share the same circuit with high draw items such as stamping equipment, refrigerators and water coolers?
What type of electrical switches and receptacles are used within your facility, industrial, commercial or residential?
I believe a person needs to start a gradual replacement of all residential switches and receptacles with at least high end commercial ones. Herb Goldstein suggested I do for my own home. If wiring techniques were the use of quick wire installation methods, you can bet you will have over time unacceptable electrical noise levels caused by the gradual weakening of the small amount of conductor material holding the quick wire in place. I experienced noise levels that were off the chart. I replaced all of them and noise and trash levels dropped substantially. I know binding post wiring is a pain, but you soon see the results. I never had a device warm to the touch after that.
At the El Paso Federal Courthouse, Herb’s folks found grounding rods almost totally corroded and had to be replaced before anything worked properly especially the CCTV cameras. Even after grounding was corrected, common and normal noise levels were staggering and power conditioners had to be placed ahead of each of the 75 cameras in the court’s system.
I believe many electrical problems could be rectified by some good quality low impedance transformer based power conditioners for the camera power and coaxial. But just constitutes a good power conditioner?
1) Your desire is to obtain a low impedance power conditioner which consists of an input protective network, a unique isolation transformer and an output filter assembly.
2) The main purpose of the transformer is to allow the bonding of neutral and ground conductors on the output side of the transformer. This effectively eliminates common mode noise allowing the ground reference to be reestablished.
3) The transformer also provides excellent noise rejection between line and neutral. The output filter assembly ties line and neutral together at high frequencies. This assures that all remaining noise is eliminated or attenuated to a safe level, yet passes the harmless lower frequencies necessary for efficient power transfer.
4) The power conditioner must not have any bypass feature or features for any reason. Bypass allows raw unfiltered electricity to enter your electronics, thus damaging or destroying it. That would defeat the basic reason you purchased the conditioner in the first place.
These then are the basic Electrical/Electronic/Communications/Operating Power Requirements of the conditioner. These then are the testing parameters you look for: It must be assumed the facility electrical system may not have been installed or maintained in accordance with the National Electrical Code® (NEC®) or local electrical codes. The unit shall be built to Underwriters Laboratories® (UL®) standards and will conform to the general requirements of American National Standards Institute® (ANSI®) and the institute of Electrical and Electronics Engineers® (IEEE®) as specified by UL® 991. Electronic protection devices must be built-into the unit. If not provided as a standard feature, add-on devices shall be built-in and become an integral part of the unit. The conditions of passing the UL® 991 test requirements shall be that the unit must remain fully operational without any operator adjustment during or after being subjected to any or all of the UL® 991 tests as specified and modified as indicated below:
a) Overvoltage and undervoltage tests, Section 10, UL® 991.
b) Power supply interruption test, Section 11, UL® 991. Modification: Interruption time need not exceed 100 milliseconds (ms).
c) Transient overvoltage test, Section 12, UL® 991. Note: Voltage and current levels will be as prescribed by paragraph 12.8. Commercially available surge generators can be substituted for test circuits shown in Figures 12.3 and 12.4.
d) Ramp voltage tests, Section 13, UL® 991.
e) Electromagnetic susceptibility tests, Section 14, UL® 991. Modification: Commercially available fast transient (noise) generators that produce equivalent noise, amplitude and frequency characteristics as defined in paragraph 14.4 and shown in Figure 14.3, may be substituted for this test.
f) Radiated electromagnetic interference (EMI) test, Section 14.8, UL® 991. Hand-held radios, cellular phones and like emitters shall not interfere with detector operation.
g) Electrostatic discharge (ESD) test, Sections 15.1.2 to 15.3.3, only. Static discharge from any source shall not interfere with unit operation.
h) The unit shall be immune to the effects of high frequency noise, 3 to 30 megahertz (MHZ); shall be immune to normal mode noise above 10 volts and immune to common mode noise above 0.5 (½) volt.
Enjoy the day,
Bill
Comment