How do we power all our equipment, and what if commercial power goes out? In the North-East corner of the Ops Room, on the back if the kitchen wall we have some circuit breaker boxes. This is a 50 to 60 year old former federal building that was occupied by the FCC. There are at least 16 conduits connected to these two boxes. Every electric contractor that has looked at this says that it would be cheaper to replace everything with new wiring rather than try to figure out this FCC legacy.
North Side of the Ops Room
The blue modular furniture was acquired from the Anchorage Blood Bank when they moved into a new building. You might notice the duplex outlets built into both the posts and beams of the risers above the desktop. For out purposes it would be better if 90% of the outlets were on the back of the risers. We can’t just spin the risers around 180 degrees. Our operating positions look messy enough as it is. If we had power cords hanging off the front of the risers and flopping on the desktops, we would never win the good housekeeping award.
Almost all of our radio equipment runs on 12 volt DC power. The computers, monitors, and some odd ball power supplies need regular 120 volt AC wall outlet power.
At the bottom center of the picture is a black box about the size of a traditional tower PC.
North side UPS
On the left is an APC Smart UPS 2200VA Tower. Inside the blue cabinet on the right is an APC Smart UPS 2200VA 2U. This UPS was designed to be mounted in a computer rack typically used in a commercial computer room.
The UPS tower is about 18″ high, 8″ wide, 22″ deep, and weighs about 110 pounds.
An APC Replacement Battery Cartridge #55 is about 6.88″ high, 5.6″ wide, 7.2″ deep, and weighs about 54 pounds. That is pretty much all of the details about the battery that you can get out of APC.
So how long can you run 1,000 watts of load off of a 2200VA UPS. Well, 2,200 divided by 1,000, carry the 7, fudge it a bit, and my guess is at least an hour and a half. According to the web site calculator: Runtime for 1,000 Watts = 15 m 31 s
Huh? 15 minutes? How can we increase our run time? If you look above, below and behind the wood, there are four Deka Unigy batteries, and four Duracell batteries wired in to feed both UPS units, for a total of 8 large batteries.
We have increased our estimated UPS runtime by a factor of 10.
West Side Cabinets
The center of the West Side 12 Volt DC power bus. On the left side of the board are two Cooper Bussmann Eaton 100 Ampere 42V Thermal Circuit Breakers. Connected by #2 AWG cables to the 12 V batteries. The top cables connect to the Blue Sea SafetyHub 150 Fuse Block. Main power positive is the red cable on the left side of the box. This main positive power is connected through individual fuses to the rest of the red wires. All of the negative leads are connected to the right hand negative bus.
The West Side Power Bus is powered by a PowerMax Model PM4-100LK
smart charger/power supply in parallel with two 12 volt batteries. If the mains power cuts out, the batteries are already connected to the bus. Simple, reliable.
For most of our power cable needs we head across town to Polar Wire Products. They have range of products ideal for arctic conditions that remain flexible in Alaska cold conditions. You don’t want the insulation on your power cables cracking and flaking off when it gets cold.
At the far end of the medium sized cables we have an Anderson Power Pole power block. Incoming power on the left, and we can see the back of three radios plugged into the power block.
Anderson Power Poles are the world wide standard for power connections in the ham radio world. You can take your 12 volt device and plug it into any 12 volt power supply that is run by commercial power, or a to-go battery box, or a solar panel, or the power system in a vehicle.
Walter – KL7WY