Since I can't find a local person who knows this stuff, BatLabs is the next best thing!
Does you dispatch point / transmitter site have emergency power?
If it's a genset, how many days fuel do you have at full load?
If is battery or UPS, how much hold out time do you have?
Do you have a provision for an external emergency power feed? IE trailer or portable genset.
I can find info on grounding and towers, but nothing on power system! Is this something there is an standard on?
Martin
Backup Power Requirements
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spareparts
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At all of my 10 sites we have the following:
8 Hrs. Microwave Battery Capacity
40 Minutes UPS at full transmitter load (all 28 channels) with dual 18KVA units and battery banks.
3 days generator capacity at full load (1000 gallons fuel on site)
We have found that our UPS capacity is currently around 2 hours with the load we have right now. Haven't had a reason to run the generators that long, but I would feel comfortable running 5 days continuous.
8 Hrs. Microwave Battery Capacity
40 Minutes UPS at full transmitter load (all 28 channels) with dual 18KVA units and battery banks.
3 days generator capacity at full load (1000 gallons fuel on site)
We have found that our UPS capacity is currently around 2 hours with the load we have right now. Haven't had a reason to run the generators that long, but I would feel comfortable running 5 days continuous.
Now you've got me wondering. We have a big-ass auto-start generator at our main site. This generator supplies:
Firehouse (the whole building)
Fire, police, and DPW radio systems
Verizon
Cingular
AT&T
Sprint
CrapTel
Voicestream (I think)
It is a huge generator that supplies I think 100 amps to each of the above. I don't for the life of me know how much fuel the thing has though. It's a diesel. The good thing though is the pumps for refueling the apparatus are about 20 feet away so we could refuel it very easily
The police quantar has a bunch of batteries at the bottom of it's cabinet. No idea how long they would last.
Our FD's low band Aerotron has a big-ass marine battery that I'm told will last a VERY long time since we don't do a lot of transmitting with it.
Our FD"s new UHF repeater on has a little 7ah battery. It draws about 7 amps on TX and only a few hundred mAh at idle. It would probably last a while but it is on my upgrade list. I plan on putting a nice bigass rack-mount UPS on the new rack for fire and DPW.
Between the batteries, a UPS, and the generator coming on in about 2.4 seconds, I am very confident we can continue working without interuption if there is a power failiure during a significant incident (Even if the generator fails).
I am in the process of building some power fail and generator fail alarms the will tie in as supervisory alarms on our Notifier fire alarm system which is monitored by dispatch.
Firehouse (the whole building)
Fire, police, and DPW radio systems
Verizon
Cingular
AT&T
Sprint
CrapTel
Voicestream (I think)
It is a huge generator that supplies I think 100 amps to each of the above. I don't for the life of me know how much fuel the thing has though. It's a diesel. The good thing though is the pumps for refueling the apparatus are about 20 feet away so we could refuel it very easily
The police quantar has a bunch of batteries at the bottom of it's cabinet. No idea how long they would last.
Our FD's low band Aerotron has a big-ass marine battery that I'm told will last a VERY long time since we don't do a lot of transmitting with it.
Our FD"s new UHF repeater on has a little 7ah battery. It draws about 7 amps on TX and only a few hundred mAh at idle. It would probably last a while but it is on my upgrade list. I plan on putting a nice bigass rack-mount UPS on the new rack for fire and DPW.
Between the batteries, a UPS, and the generator coming on in about 2.4 seconds, I am very confident we can continue working without interuption if there is a power failiure during a significant incident (Even if the generator fails).
I am in the process of building some power fail and generator fail alarms the will tie in as supervisory alarms on our Notifier fire alarm system which is monitored by dispatch.
"I'll eat you like a plate of bacon and eggs in the morning. "
- Some loser on rr.com
eBay at it's finest:
Me: "What exactly is a 900Mhz UHF CB?"
Them: "A very nice CB at 900Mhz speed!"
- Some loser on rr.com
eBay at it's finest:
Me: "What exactly is a 900Mhz UHF CB?"
Them: "A very nice CB at 900Mhz speed!"
Dispatch site has 3 hours of UPS powering all console equipment and base stations, in addtion Radio consoles (Zetron) have battery backup power supplys and basestations have backup batterys.
Then there is a 100KW Natural Gas powered generator with auto transfer switch to power the UPS. If all else fails there is a manual transfer switch to a external inlet that can be supplyed by a diesel trailer mounted generator or the pto generator on the rescue.
Remote sites have base station batterys and natural gas generators.
the Dispatch site has backup basestations for the entire system so it could functon without the remote sites in the event they where lost. The remote sites have all the main UHF freqs that we normaly use and can tone out the department with the backup encoder if the dispatch site was lost.
The only problem we have ever had was a transfer switch that stuck in the neutral postion during the weekly test.
Handled the big blackout last summer, had full communications on our UHF system while the depts that went to Nextel had nothing, they should have stayed on LowBand.
Then there is a 100KW Natural Gas powered generator with auto transfer switch to power the UPS. If all else fails there is a manual transfer switch to a external inlet that can be supplyed by a diesel trailer mounted generator or the pto generator on the rescue.
Remote sites have base station batterys and natural gas generators.
the Dispatch site has backup basestations for the entire system so it could functon without the remote sites in the event they where lost. The remote sites have all the main UHF freqs that we normaly use and can tone out the department with the backup encoder if the dispatch site was lost.
The only problem we have ever had was a transfer switch that stuck in the neutral postion during the weekly test.
Handled the big blackout last summer, had full communications on our UHF system while the depts that went to Nextel had nothing, they should have stayed on LowBand.
Cause Motorola said so that's why
A couple of points to ponder about emergency power generators. First, if it is a diesel, it should have a load when it is run. Most diesels engines like to work. To run them with no load will what is called "Wet Stack" the engine. This is unburned fuel filling up the intake and exhaust manifolds. Over time you may see a black or brown stain going down from the manifolds.
I like to see a full load test put on a generator at least once a year. This makes sure that the engine can deliver the required power. Run the load for at least an hour. If there was any moisture collecting in the engine, it will be evaporated during this load test. It also will help reseat the rings. Carbon has a tendency to build up with light use. This causes excess oil to be used.
Second, make sure that you exercise the generator under load. This checks out the entire system. It causes the auto transfer switch to move. I have seen the ATS rust in one position because the people running the show didn't want the power glitch when it went between normal and emergency. I keep asking them what they are going to do when the power goes out. You will get a major glitch when that happens.
Third, bear in mind that an engine will not run forever. Just because you have 3 weeks of fuel, or natural gas, don't forget that the engine oild will have to be changed after so many hours. This normally is in the order of 100 to 300 hours. Some of the junk generators like the small Coleman 3600 RPM units only get 50 hours on an oil change. You heard me, 2 days and the oil needs changing. Not my idea of a good backup power system.
Forth reason for having an active generator, is to make sure the voltage and frequency are correct. Some diesel generators with a mechanical governor, will gum up with no use. When you need it, the engine won't run at the correct speed. This issue is normally found only on older generators that have had little or no service done to them.
When the generator is run, it should be operating for about 20 to 30 minutes at the minimum. This way the engine will heat up and evaporate moisture that collect. Oil will turn kind of a milky brown when it gets water in it. If you see this on the oil dip stick, you need to change the oil and filter right now. Run the engine and see if it clears up. It may even take a second iol change and another filter.
Don't forget to change the antifreeze and oil on a regular basis. I changed the coolant on a cellular carrier's generator last month that smelled like a swamp. I would bet that it hadn't been changed since it was bought some 10 years ago. You can stretch it for 2 years, but then it needs to be changed.
The battery should be changed out every 2 years at the outside. Many of these generators have a trickle charger that kills a battery. What you should have is a battery maintainer. This unit will kind of only pulse the battery every once in a while. If the voltage goes down, then it will kick in, bring up the voltage and then go back to the maintain mode.
Hope this gives a few ideas to those maintaining sites.
Jim
I like to see a full load test put on a generator at least once a year. This makes sure that the engine can deliver the required power. Run the load for at least an hour. If there was any moisture collecting in the engine, it will be evaporated during this load test. It also will help reseat the rings. Carbon has a tendency to build up with light use. This causes excess oil to be used.
Second, make sure that you exercise the generator under load. This checks out the entire system. It causes the auto transfer switch to move. I have seen the ATS rust in one position because the people running the show didn't want the power glitch when it went between normal and emergency. I keep asking them what they are going to do when the power goes out. You will get a major glitch when that happens.
Third, bear in mind that an engine will not run forever. Just because you have 3 weeks of fuel, or natural gas, don't forget that the engine oild will have to be changed after so many hours. This normally is in the order of 100 to 300 hours. Some of the junk generators like the small Coleman 3600 RPM units only get 50 hours on an oil change. You heard me, 2 days and the oil needs changing. Not my idea of a good backup power system.
Forth reason for having an active generator, is to make sure the voltage and frequency are correct. Some diesel generators with a mechanical governor, will gum up with no use. When you need it, the engine won't run at the correct speed. This issue is normally found only on older generators that have had little or no service done to them.
When the generator is run, it should be operating for about 20 to 30 minutes at the minimum. This way the engine will heat up and evaporate moisture that collect. Oil will turn kind of a milky brown when it gets water in it. If you see this on the oil dip stick, you need to change the oil and filter right now. Run the engine and see if it clears up. It may even take a second iol change and another filter.
Don't forget to change the antifreeze and oil on a regular basis. I changed the coolant on a cellular carrier's generator last month that smelled like a swamp. I would bet that it hadn't been changed since it was bought some 10 years ago. You can stretch it for 2 years, but then it needs to be changed.
The battery should be changed out every 2 years at the outside. Many of these generators have a trickle charger that kills a battery. What you should have is a battery maintainer. This unit will kind of only pulse the battery every once in a while. If the voltage goes down, then it will kick in, bring up the voltage and then go back to the maintain mode.
Hope this gives a few ideas to those maintaining sites.
Jim
Primary PSAP, 4 hours UPS, Diesel fired generator/7 days fuel
Secondary PSAP, gas roll out generator, 3-4days of gas on hand.
Remote sites are all 2-3days battery with enough solar panels to run them 50% indefinetly (unless there is a total eclipse
)
Solar is a viable option here in Colorado. I have a repeater site and a remote receive site that are solar only.
Howard
Secondary PSAP, gas roll out generator, 3-4days of gas on hand.
Remote sites are all 2-3days battery with enough solar panels to run them 50% indefinetly (unless there is a total eclipse
)Solar is a viable option here in Colorado. I have a repeater site and a remote receive site that are solar only.
Howard