I'm going to be installing some temperature monitoring our radio tower equipment hut. If the AC or heat fails, I want to know about so it will send a supervisory alarm to our fire system. I need to know what a good high and low temperature setting would be. This room contains:
(1) Kenwood TKR-850 repeater
(1) Kenwood TKR-750 repeater
(1) Aerotron low band base
(1) Motorola high power Quantar
The kenwood manual states it's operating temp is -22F to +140F which seems like a stretch to me but who knows. What about the Quantar? The AC is usually set for about 72F and the heat set for around 60F.
Min / Max temperature for radio room
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Min / Max temperature for radio room
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Them: "A very nice CB at 900Mhz speed!"
Our equipment room at work has a lot more than that, and we run the A/C constantly to keep the room at 75 degrees. I'll take a picture on Sunday and post it to illustrate how crowded it is... Prior to the county network and server storage stuff got there it was not uncommon to have that room at 60 degrees.
But our phone system sends out an alarm when the eqipment gets above 90 degrees. I wouldn't worry about too coold too much unless you plan on turning the equipment room into a freezer. But I would try to keep it below 85-90 degrees. That is just my experience with our back room.
But our phone system sends out an alarm when the eqipment gets above 90 degrees. I wouldn't worry about too coold too much unless you plan on turning the equipment room into a freezer. But I would try to keep it below 85-90 degrees. That is just my experience with our back room.
JAYMZ
"Mom and dad say I should make my life an example of the principles I believe in. But every time I do, they tell me to stop it."
Calvin
"Mom and dad say I should make my life an example of the principles I believe in. But every time I do, they tell me to stop it."
Calvin
My Nucleus manual has the same limits: -22F to +140F, however I wouldn't want to be the person having to service it at those extremes.
Probably a good rule of thumb is whatever is comfortable to humans will more than likely be way too good for the equipment. I'd be concerned below 40F or above 100F, although your heat/AC equipment should have kept it closer to 70F under normal circumstances. Depending on how long it would take a repairman to come fix an environmental failure, you can determine how cold or hot the room will get in that time frame.
If you can measure the power drawn by the equipment, you might be able to figure the wattage being drawn in and wasted as heat. There are probably ways to figure the BTU/hr from that, and you can do a real study on it to figure the heat rise from the equipment running.
Modern electronic equipment probably won't care about the cold temps, but it will get upset when the temp gets way too high. If there are fans inside stirring up the air, that will help quite a bit. Unless your equipment is in an attic under a hot tin roof, it'll probably survive most New England weather extremes. About the only thing I'd worry about, is frequency stability with older equipment. New stuff either uses ovens or temp compensated crystals to keep them on frequency.
I know of an AM broadcast station with no heat in the transmitter building. The solid state equipment didn't generate more than a few hundred watts of heat, and the building has very thin, uninsulated walls. It didn't complain at 0F and had no problems at over 90F when the AC froze up.
Bob M.
Probably a good rule of thumb is whatever is comfortable to humans will more than likely be way too good for the equipment. I'd be concerned below 40F or above 100F, although your heat/AC equipment should have kept it closer to 70F under normal circumstances. Depending on how long it would take a repairman to come fix an environmental failure, you can determine how cold or hot the room will get in that time frame.
If you can measure the power drawn by the equipment, you might be able to figure the wattage being drawn in and wasted as heat. There are probably ways to figure the BTU/hr from that, and you can do a real study on it to figure the heat rise from the equipment running.
Modern electronic equipment probably won't care about the cold temps, but it will get upset when the temp gets way too high. If there are fans inside stirring up the air, that will help quite a bit. Unless your equipment is in an attic under a hot tin roof, it'll probably survive most New England weather extremes. About the only thing I'd worry about, is frequency stability with older equipment. New stuff either uses ovens or temp compensated crystals to keep them on frequency.
I know of an AM broadcast station with no heat in the transmitter building. The solid state equipment didn't generate more than a few hundred watts of heat, and the building has very thin, uninsulated walls. It didn't complain at 0F and had no problems at over 90F when the AC froze up.
Bob M.
Re: Min / Max temperature for radio room
One thing that you need to keep in mind is that solid state electronics will self destruct when their junction temps get too high. One of the best ways to find out just how warm a peice of equipment is operating is to place your hand carefully on it. If you can't hold your hand on the metal of the case or heat sink, your headed to an early repair or replacement.
The cooler you can operate the equipment the better off you are. Then on the other end of the scale, if the electronics gets too cold, the gain of the transistors starts to drop the colder they get. At some point you will start to see strange failures or funny operation of the equipment.
Also bear in mind that the temperature range the radios will operate over is a function on what grade of components are used in the radios. With the way the market is going today, I wouldn't want to bet my life on a radio that was in a room operating at a temperature much above 85 or 90. Your just creating early failure the hotter you go. On the cold side, I would try to keep the room no lower than around 40.
You will find radios operating lower than 40, but I would bet they start showing strange problems. I had one that we had to put a lightbulb in during the winter with a thermostat. It would generate a spur on the local police channel when it got below about 20.
Jim
[quote="nmfire10"]I'm going to be installing some temperature monitoring our radio tower equipment hut. If the AC or heat fails, I want to know about so it will send a supervisory alarm to our fire system. I need to know what a good high and low temperature setting would be. This room contains:
(1) Kenwood TKR-850 repeater
(1) Kenwood TKR-750 repeater
(1) Aerotron low band base
(1) Motorola high power Quantar
The kenwood manual states it's operating temp is -22F to +140F which seems like a stretch to me but who knows. What about the Quantar? The AC is usually set for about 72F and the heat set for around 60F.[/quote]
The cooler you can operate the equipment the better off you are. Then on the other end of the scale, if the electronics gets too cold, the gain of the transistors starts to drop the colder they get. At some point you will start to see strange failures or funny operation of the equipment.
Also bear in mind that the temperature range the radios will operate over is a function on what grade of components are used in the radios. With the way the market is going today, I wouldn't want to bet my life on a radio that was in a room operating at a temperature much above 85 or 90. Your just creating early failure the hotter you go. On the cold side, I would try to keep the room no lower than around 40.
You will find radios operating lower than 40, but I would bet they start showing strange problems. I had one that we had to put a lightbulb in during the winter with a thermostat. It would generate a spur on the local police channel when it got below about 20.
Jim
[quote="nmfire10"]I'm going to be installing some temperature monitoring our radio tower equipment hut. If the AC or heat fails, I want to know about so it will send a supervisory alarm to our fire system. I need to know what a good high and low temperature setting would be. This room contains:
(1) Kenwood TKR-850 repeater
(1) Kenwood TKR-750 repeater
(1) Aerotron low band base
(1) Motorola high power Quantar
The kenwood manual states it's operating temp is -22F to +140F which seems like a stretch to me but who knows. What about the Quantar? The AC is usually set for about 72F and the heat set for around 60F.[/quote]
Speaking of our wonderful equipment room....
The AC unit (once again failed) and under a few hours, all the servers (county wide) started going south pretty quick. The room temp at the far end was at least 100. The needle on the theromstat was buried.
We kept the one at the PD around 60, and worked well. At the place before that, we had 1 CEB, 1 server and the recorder in a decent sized room. If we closed the door in there, the room became warm fairly quickly.
The AC unit (once again failed) and under a few hours, all the servers (county wide) started going south pretty quick. The room temp at the far end was at least 100. The needle on the theromstat was buried.
We kept the one at the PD around 60, and worked well. At the place before that, we had 1 CEB, 1 server and the recorder in a decent sized room. If we closed the door in there, the room became warm fairly quickly.
Lowband radio. The original and non-complicated wide area interoperable communications system
someone shut off the AC in our equipment room at work. It has along the lines of 10 DVR's, Mirra recorder, multiplexers and controllers, several servers and PC's, a UPS that is almost as tall as me, and the CEB. With the Liebert AC unit off and just the one little vent in the cieling not doing much, it got up to 90.
"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!"
Another thing worth checking, if applicable, is the sprinkler head activation temperature in your equipment room.
A friend of mine used to manage a data center. One night the guard came into his office and said "It's really hot in that room with all of those boxes." He investigated a bit and found that the AC had failed and the computer room was up to 108 degrees!
A little further investigation the next day found that they had installed (if memory serves) 115 degree bursts on the sprinkler heads, thinking they would help protect the equipment by activating earlier in case of a fire. Apparently no one ever considered the equipment room reaching that temperature without a fire.
They changed those bursts in a hurry
A friend of mine used to manage a data center. One night the guard came into his office and said "It's really hot in that room with all of those boxes." He investigated a bit and found that the AC had failed and the computer room was up to 108 degrees!
A little further investigation the next day found that they had installed (if memory serves) 115 degree bursts on the sprinkler heads, thinking they would help protect the equipment by activating earlier in case of a fire. Apparently no one ever considered the equipment room reaching that temperature without a fire.
They changed those bursts in a hurry
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spareparts
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Min/Max Temperature
To answer the original question, it depends what your operating setpoints are, and if you are using any "occupied" and "unoccupied" modes that would change the room temperature. You must consider the normal swings between the two. Assuming your heat and A/C are sized appropriately, your unoccupied set points might be 60F (heat) and 75F (cool). Your alarm points can be 50F (not so important), and 85F. Your equipment should stay within these bounds.
One tip if you haven't yet selected the monitoring equipment: See if you can get analog values out of it and not just a digital high temp alarm. For instance, if you do get a high temp alarm, do you wish to know just how high it actually is? This will help you decide if you have to go fix it right away (overtime rates might apply) or if it can wait until morning. There are other advantages too.
For the equipment you state, they can tolerate higher temperatures. The human servicing them would get uncomfortable first. Just keep air flow across equipment and you will be fine.
Except any battery that you may have providing backup power. They like 77F which is the standard float voltage temperature. As your steady state operating temperature goes upward, float voltage must be compensated downward and your battery life will be shortened.
If anyone wants to expand this discussion for free air cooling or emergency ventilation, then the alarm set points will have to be expanded wider. However, things aren't as bad as you might think depending on your local ambient temperatures. Open a new discussion in the infrastructure group and we can delve into this a bit deeper .
RF Dude
One tip if you haven't yet selected the monitoring equipment: See if you can get analog values out of it and not just a digital high temp alarm. For instance, if you do get a high temp alarm, do you wish to know just how high it actually is? This will help you decide if you have to go fix it right away (overtime rates might apply) or if it can wait until morning. There are other advantages too.
For the equipment you state, they can tolerate higher temperatures. The human servicing them would get uncomfortable first. Just keep air flow across equipment and you will be fine.
Except any battery that you may have providing backup power. They like 77F which is the standard float voltage temperature. As your steady state operating temperature goes upward, float voltage must be compensated downward and your battery life will be shortened.
If anyone wants to expand this discussion for free air cooling or emergency ventilation, then the alarm set points will have to be expanded wider. However, things aren't as bad as you might think depending on your local ambient temperatures. Open a new discussion in the infrastructure group and we can delve into this a bit deeper .
RF Dude
According to the Quantar manual (68P81096E56-A, p. 3): "The following are a few of the standard Quantar features: . . . Wide operating temperature range: -30C to +60C (-22F to 140F)."
That said, allowing the radio room temperature to get much about 90 for an extended period of time imposes some stress on the equipment. Also, high temperatures are often accompanied by high humidity, and often the dehumidification function of AC is as important as the cooling function.
If what you want is an alarm that will tell you that the AC has failed, simply set the alarm trip for 10 degrees above the nominal setting of the AC thermostat (once you've verified that your AC unit is capable of maintaining its thermostat temperature when all the toys are running).
That said, allowing the radio room temperature to get much about 90 for an extended period of time imposes some stress on the equipment. Also, high temperatures are often accompanied by high humidity, and often the dehumidification function of AC is as important as the cooling function.
If what you want is an alarm that will tell you that the AC has failed, simply set the alarm trip for 10 degrees above the nominal setting of the AC thermostat (once you've verified that your AC unit is capable of maintaining its thermostat temperature when all the toys are running).
Thanks for the input guys. A few points to answer RF Dude's questions:
We do have several batteries in there. The Aerotron has a big arse deep cycle battery and it float charges itself. The Kenwood's have some 10 amp sealed lead acid batteries that are float charged. The Quantar has some big lead acid batteries also. I never thought of those things being uncomfortable. How come this isn't a problem in a car when it is 120 degrees outside?
I'm not worried about knowing the exact temperature. There is no means to report that anyway. The analog temp monitors are going to provide contact closure to a monitor module on our fire alarm system. That will in turn report a supervisory alarm to dispatch. They will call me and the call list. Someone will always be around to check it and OT isn't a problem in a volunteer company
So I think I've settled on 45 for low and 85 for high. I'm not wasting power heating the room to 55 or 60 degrees in the winter, if someone is working in there, they can turn the heat up. If it goes above 85, there is definately something wrong with the AC.
We do have several batteries in there. The Aerotron has a big arse deep cycle battery and it float charges itself. The Kenwood's have some 10 amp sealed lead acid batteries that are float charged. The Quantar has some big lead acid batteries also. I never thought of those things being uncomfortable. How come this isn't a problem in a car when it is 120 degrees outside?
I'm not worried about knowing the exact temperature. There is no means to report that anyway. The analog temp monitors are going to provide contact closure to a monitor module on our fire alarm system. That will in turn report a supervisory alarm to dispatch. They will call me and the call list. Someone will always be around to check it and OT isn't a problem in a volunteer company
So I think I've settled on 45 for low and 85 for high. I'm not wasting power heating the room to 55 or 60 degrees in the winter, if someone is working in there, they can turn the heat up. If it goes above 85, there is definately something wrong with the AC.
"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!"
As I promised... our busy equipment room. It's about 10x30. Sorry about the poor quality pictures, I almost forgot that I was going to post these. I took the pix with the camera on my Cell Phone.Pj wrote:Speaking of our wonderful equipment room....
The Server racks.
JAYMZ
"Mom and dad say I should make my life an example of the principles I believe in. But every time I do, they tell me to stop it."
Calvin
"Mom and dad say I should make my life an example of the principles I believe in. But every time I do, they tell me to stop it."
Calvin
Re: :
Verizon, Motorola E815Jim2121 wrote:nice pic's from the cellphone! what's the make & model of the phone?
JAYMZ
"Mom and dad say I should make my life an example of the principles I believe in. But every time I do, they tell me to stop it."
Calvin
"Mom and dad say I should make my life an example of the principles I believe in. But every time I do, they tell me to stop it."
Calvin
Battery temp
Using SI measurements, the normal float temperature for a VRLA battery is 25C. Every 10C above 25C will result in a 50% reduction in battery life. That is assuming that a temperature compensated float is used. If not, I've seen brand new batteries crack and die in a year at 35C. The battery capacity is designed around the load and desired battery run time. Basic engineering for engineered systems. In a power outage, you have expectations that the comm system will be there for x hours while you mobilize a generator, etc.
Car batteries are wet cells which are a bit more tolerant of heat. Keep in mind that some manufacturers used to put the battery under the back seat to avoid the engine heat or to reduce temperature variations. As long as it can start your car and deliver some cranking current, most people think all is fine. You replace the battery when it is obvious that leaving a dome light on for a few hours kills the battery, or it simply won't start the car anymore. I replaced a 5 year old car battery once in the former example. Leaving anything on would kill the battery in a short time. But it would still start the car under good (no parasitic drain) conditions. After I replaced it, for curiosity I did a discharge test on the battery and got 6 AHr. I was amused that it got to this point without a bad cell so to speak. A new battery for my car is 65 AHr.
Regarding humidity, I did some extensive testing on free air cooling. Humidity doesn't seem to be a comfort issue for electronics. Rather, many equipment manufacturers specify 5 to 95% NON-CONDENSING humidity. I did my tests using temperature and hygrometer data loggers. It will always be a bit warmer INSIDE the shelter than outside. Any increase in temperature will lower the relative humidity. This means that even with FOG outside, you will not have fog (condensing humidity) inside as long as things are a couple degrees warmer. It will be humid, but you should not have a dew point. To have a dew point on the equipment, it will have to be cooler inside than outside. For instance, opening the door of a heavily air conditioned shelter (or your freezer / fridge?) in a tropical or humid environment. Perhaps if a shelter produces little or no significant heat will interior dew point be an issue under certain weather conditions.
RF Dude.
Car batteries are wet cells which are a bit more tolerant of heat. Keep in mind that some manufacturers used to put the battery under the back seat to avoid the engine heat or to reduce temperature variations. As long as it can start your car and deliver some cranking current, most people think all is fine. You replace the battery when it is obvious that leaving a dome light on for a few hours kills the battery, or it simply won't start the car anymore. I replaced a 5 year old car battery once in the former example. Leaving anything on would kill the battery in a short time. But it would still start the car under good (no parasitic drain) conditions. After I replaced it, for curiosity I did a discharge test on the battery and got 6 AHr. I was amused that it got to this point without a bad cell so to speak. A new battery for my car is 65 AHr.
Regarding humidity, I did some extensive testing on free air cooling. Humidity doesn't seem to be a comfort issue for electronics. Rather, many equipment manufacturers specify 5 to 95% NON-CONDENSING humidity. I did my tests using temperature and hygrometer data loggers. It will always be a bit warmer INSIDE the shelter than outside. Any increase in temperature will lower the relative humidity. This means that even with FOG outside, you will not have fog (condensing humidity) inside as long as things are a couple degrees warmer. It will be humid, but you should not have a dew point. To have a dew point on the equipment, it will have to be cooler inside than outside. For instance, opening the door of a heavily air conditioned shelter (or your freezer / fridge?) in a tropical or humid environment. Perhaps if a shelter produces little or no significant heat will interior dew point be an issue under certain weather conditions.
RF Dude.
RFDude
Sprinklers in a computer room are something to be concerned about in themselves. Sprinklers on for us means goodbye to $3,500,000 worth of gear.HumHead wrote:Another thing worth checking, if applicable, is the sprinkler head activation temperature in your equipment room.
A friend of mine used to manage a data center. One night the guard came into his office and said "It's really hot in that room with all of those boxes." He investigated a bit and found that the AC had failed and the computer room was up to 108 degrees!
A little further investigation the next day found that they had installed (if memory serves) 115 degree bursts on the sprinkler heads, thinking they would help protect the equipment by activating earlier in case of a fire. Apparently no one ever considered the equipment room reaching that temperature without a fire.
They changed those bursts in a hurry
Our computer rooms only have a halon replacement called FE-13.
FE-13
FE-13... I looked it up in the Dupont web page. See http://www.dupont.com/fire/properties/index.html .
FE-13 has an atmosheric lifetime of 264 years and the largest Global Warning contribution of all the listed agents.
Check out NOVEC from 3M. It has ZERO ozone depletion, and lasts only a few days in the atmosphere.
We have lots of Halon that will never be replaced. If it goes off... (sometimes due to a lightning hit with a bit of smoke lingering) it cannot be refilled. So we have lots of FM-200, but it is just a bit better than your FE-13 for atmospheric life.
I'd buy Novec, but would you believe that greenpeace people running our environmental group want only Inergen.... 3000 PSI bombs of inert gas. No thanks.
Life just isn't simple anymore.
FE-13 has an atmosheric lifetime of 264 years and the largest Global Warning contribution of all the listed agents.
Check out NOVEC from 3M. It has ZERO ozone depletion, and lasts only a few days in the atmosphere.
We have lots of Halon that will never be replaced. If it goes off... (sometimes due to a lightning hit with a bit of smoke lingering) it cannot be refilled. So we have lots of FM-200, but it is just a bit better than your FE-13 for atmospheric life.
I'd buy Novec, but would you believe that greenpeace people running our environmental group want only Inergen.... 3000 PSI bombs of inert gas. No thanks.
Life just isn't simple anymore.
RFDude