We have installed a system at work using multiple MTR2000's and Argus power supplies. This is the equipment Motorola sugessted and sells for the MTR. The Argus is a battery switch and charger in one unit.
My question is we have blown 4 out 8 of the MTR power supplies (CLN....) in this arangement. I asked Motorola Tech Support about this and was told they have never had this problem.
Has any one out there seen this or used this configuration ? I know this is not the preferred way to run this system, however the engineer designed it not the installers. It has been brought up about running the bases completly from DC but doesn't go anywhere.
Any help on the Argus would be great.
Jeff S
MTR2000 and Argus Power Supply
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We have set-up many MTR2000 repeaters with the Argus battery revert systems with great success. I have yet to see a power supply failure in this configuration. I don't see how it could be the Argus unit at fault, since it remains isolated from the repeater unless the A/C power fails. Upon A/C failure, the Argus immediately switches the DC battery power to the repeater, fast enough that the repeater doesn't do a power-on reset. Then again, our sites seem to have reliable primary power, the revert isn't used that often. Perhaps your sites experience repeated periods of on/off flickering power? That might cause something to fail.
Todd
Todd
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The Argus only supplies DC power to the MTR2000 when the AC power to the ARGUS fails and presumably also to the MTR2000 at the same time. When this happens, the Argus disconnects the batteries from its charger and connects the batteries to the MTR2000. Completely keeping the charger isolated from the MTR2000.
If there is no possibility for the MTR2000 supply to feed power into the battery, and I believe there isn’t, then the Argus or a defective battery can’t cause the failure. If there is power coming from the MTR2000 battery connector, then it is very well possible that an increased load from a near dead battery during switch over causes the MTR2000 power supply to fail. My guess is that the MTR2000 has an isolation diode in series with its battery power connector to prevent this from happening since it isn’t designed to charge batteries. I suggest you check that there isn’t any significant power coming from the MTR2000 battery connector.
All the MTR2000’s we use are configured the same way, each with its own Argus charger and battery. The only time the MTR2000 supply blows is when lightning hits, and only the internal fuse blows.
Nand.
If there is no possibility for the MTR2000 supply to feed power into the battery, and I believe there isn’t, then the Argus or a defective battery can’t cause the failure. If there is power coming from the MTR2000 battery connector, then it is very well possible that an increased load from a near dead battery during switch over causes the MTR2000 power supply to fail. My guess is that the MTR2000 has an isolation diode in series with its battery power connector to prevent this from happening since it isn’t designed to charge batteries. I suggest you check that there isn’t any significant power coming from the MTR2000 battery connector.
All the MTR2000’s we use are configured the same way, each with its own Argus charger and battery. The only time the MTR2000 supply blows is when lightning hits, and only the internal fuse blows.
Nand.
We have never been able to get ANY information, schematics, ect;, from Argus. No support what so ever.
We use DuraComm battery backup kits.
The battery revert connector on the power supply connects directly to the filter stage. It CAN and DOES feed directly to the battery unless a disconnect is used (Argus) external to the station or a isolation diode. If not when AC power is restored the power supply sees a very discharged battery that can look like a short, blowing out the power supply switching/filter stage.
We use DuraComm battery backup kits.
The battery revert connector on the power supply connects directly to the filter stage. It CAN and DOES feed directly to the battery unless a disconnect is used (Argus) external to the station or a isolation diode. If not when AC power is restored the power supply sees a very discharged battery that can look like a short, blowing out the power supply switching/filter stage.
Argus and MTR2000
I was looking at the MTR AC power supply schematics and the only reason I saw for NOT connecting a battery directly to the MTR is the fact that it puts out over 14V. IT would fry the battery. Is there any other reason? So the question came up if we were to use diode voltage drops to bring the voltage to say 13.8V towards the battery... A way to get around buying the Argus.
The other oddity with the MTR and Quantars is with multiple radios, they don't provide a way to use only one battery bank. Each radio/power supply/charger acts independently and requires a separate battery. It would seem cheaper and more efficient to have only one battery plant (suitably sized) and charger shared between multiple radios.
In the end, we decided to buy the MTR and Quantar DC power supplies (24V) that share a single battery and rectifier plant. This is OK for a trunked system with multiple channels... but say having 4 or less radios, being able to use the Motorola supplied power supplies with a shared battery would be cheaper.
Anyone BTDT?
RFDude
The other oddity with the MTR and Quantars is with multiple radios, they don't provide a way to use only one battery bank. Each radio/power supply/charger acts independently and requires a separate battery. It would seem cheaper and more efficient to have only one battery plant (suitably sized) and charger shared between multiple radios.
In the end, we decided to buy the MTR and Quantar DC power supplies (24V) that share a single battery and rectifier plant. This is OK for a trunked system with multiple channels... but say having 4 or less radios, being able to use the Motorola supplied power supplies with a shared battery would be cheaper.
Anyone BTDT?
RFDude
Two responses:
First, as to connecting a battery (or bank) to the DC side of a station's internal power supply, don't do it. Even if you drop the voltage to 13.8, constant voltage charging at that voltage (a/k/a "trickle charging") will fry flooded cell batteries, and most gel cell batteries, in a few months.
Second, my views on the most effective (as well as cost effective) way to back up stations like the Quantar have been set forth previously here. Do a search on "Heart Interface." We have a bunch of these power supplies running, some for years, without a hitch.
Heart Interface is basically a transfer swtich/inverter/"smart (i.e., 3-stage) charger in a single unit. While utility power is available, it is passed through to the AC-based Quantar. On loss of utility power, it switches into inverter mode so fast (about 20 ms.) that the radio never sees it and doesn't reboot. Once utility power is restored, the batteries are automatically recharged fully and properly, but can be left connected for years without cooking.
For a 110W Quantar, we use a 1 kW Heart Interface and two G27 or G31 gel cells (which can be used in occupied spaces). Though intended to serve only (a) to bridge the 20-60 seconds required for load transfer to an auto-start generator or (b) to carry load long enough to get a skid mount to the station in the event the backup genset fails, by experiment we have found that the system will carry a 90-5-5 duty cycle Quantar for more than 4 hours without approaching the 50% discharge point.
Total cost: about $1,200 (exclusive of installation, which is pretty simple).
Note that the Heart defines loss of utility power as voltage < 95 VAC RMS or >135 VAC RMS, or freq off from 60 Hz by more than 4 Hz, so the unit protects against sags and surges as well as complete outages.
The same system can be used to backup PC-based dispatch consoles (which, running under Windows NT, can severely hang in the event of a LOOP reboot), but one has to design the power requirements a bit differently for the typical installation (one sever and four workstations).
First, as to connecting a battery (or bank) to the DC side of a station's internal power supply, don't do it. Even if you drop the voltage to 13.8, constant voltage charging at that voltage (a/k/a "trickle charging") will fry flooded cell batteries, and most gel cell batteries, in a few months.
Second, my views on the most effective (as well as cost effective) way to back up stations like the Quantar have been set forth previously here. Do a search on "Heart Interface." We have a bunch of these power supplies running, some for years, without a hitch.
Heart Interface is basically a transfer swtich/inverter/"smart (i.e., 3-stage) charger in a single unit. While utility power is available, it is passed through to the AC-based Quantar. On loss of utility power, it switches into inverter mode so fast (about 20 ms.) that the radio never sees it and doesn't reboot. Once utility power is restored, the batteries are automatically recharged fully and properly, but can be left connected for years without cooking.
For a 110W Quantar, we use a 1 kW Heart Interface and two G27 or G31 gel cells (which can be used in occupied spaces). Though intended to serve only (a) to bridge the 20-60 seconds required for load transfer to an auto-start generator or (b) to carry load long enough to get a skid mount to the station in the event the backup genset fails, by experiment we have found that the system will carry a 90-5-5 duty cycle Quantar for more than 4 hours without approaching the 50% discharge point.
Total cost: about $1,200 (exclusive of installation, which is pretty simple).
Note that the Heart defines loss of utility power as voltage < 95 VAC RMS or >135 VAC RMS, or freq off from 60 Hz by more than 4 Hz, so the unit protects against sags and surges as well as complete outages.
The same system can be used to backup PC-based dispatch consoles (which, running under Windows NT, can severely hang in the event of a LOOP reboot), but one has to design the power requirements a bit differently for the typical installation (one sever and four workstations).
There are two pages in the Argus manual that try to explain what it is doing under a variety of conditions. I hate to say that after reading it several times, I am not a whole lot wiser. And since the Argus MTR2000 combination appears very reliable, I can’t offer to many suggestions with your problem.
What I did find out is that the Argus won’t allow the battery to go lower that what is good for the battery. At this low point, it will disconnect the battery from the load. This means that the battery never looks like a dead short when power is restored.
Previously I assumed that the MTR2000 power supply does not feed power out of the MTR battery connector. After checking with a meter and like others said, it can feed power out of the connector, but the Argus actually checks if there is power at the connector besides checking if the AC line is powered up. I assume the Argus is smart enough not to connect the battery to the MTR when it isn’t needed or because of an Argus failure.
The Argus is not only a battery reverting charger; it also takes care of battery maintenance by automatically equalizing the batteries after 30 days of float charging. During charging, it takes into account the battery temperature and adjusts the needed voltage accordingly.
Having 4 out of 8 MTR power supplies fail in one location does not necessarily mean that the problem is with the Argus. It could very well be a problem with a batch of components used in the MTR power supply even though Motorola never heard of this, or maybe some destructive spikes on the power line considering that nobody here mentioned a similar problem.
You could email Argus for support. They do supply an email address for this in the manual. (In lieu of diagrams I guess.)
Nand.
What I did find out is that the Argus won’t allow the battery to go lower that what is good for the battery. At this low point, it will disconnect the battery from the load. This means that the battery never looks like a dead short when power is restored.
Previously I assumed that the MTR2000 power supply does not feed power out of the MTR battery connector. After checking with a meter and like others said, it can feed power out of the connector, but the Argus actually checks if there is power at the connector besides checking if the AC line is powered up. I assume the Argus is smart enough not to connect the battery to the MTR when it isn’t needed or because of an Argus failure.
The Argus is not only a battery reverting charger; it also takes care of battery maintenance by automatically equalizing the batteries after 30 days of float charging. During charging, it takes into account the battery temperature and adjusts the needed voltage accordingly.
Having 4 out of 8 MTR power supplies fail in one location does not necessarily mean that the problem is with the Argus. It could very well be a problem with a batch of components used in the MTR power supply even though Motorola never heard of this, or maybe some destructive spikes on the power line considering that nobody here mentioned a similar problem.
You could email Argus for support. They do supply an email address for this in the manual. (In lieu of diagrams I guess.)
Nand.