Watching the weather

The weather affects many things. When the weather improves, outdoor projects like tower work can be completed. When the weather is terrible, we may need to do extra work restoring broadcast signals. Today, I am looking at Hurricane Lee, in the North Atlantic basin. Historically speaking, September is the month when we get Hurricanes in the Northeast.

As of this writing, it is too early to be concerned about Lee. Hurricanes can be very unpredictable and there is a good chance the forecast will change many times over the next week or so. That being said, this time of year is a good time to call the fuel companies and top off the generator tanks since winter is coming in a few months anyway. As the situation develops, I may need to dust off the pre-storm checklist.

The basic pre-storm checklist looks something like this:

  • 96 hours or more before the storm: Schedule fuel deliveries for generators, and top off oil and water as needed. Test generators under load if possible. Check UPS batteries. Make an off-site data backup if it does not already exist.
  • 72 hours before the storm: Coordinate with programming to have backup programs available in the event that the satellite dish is damaged, the internet goes down, etc. Inventory and restock PPE, emergency food, water, blankets, first aid supplies, batteries, etc.
  • 48 hours before the storm: Procure supplies needed to secure buildings and sites (plywood, tarps, sandbags, rope, nails, screws, etc). Work out backups for internet STL systems if possible. Work on access plans to remote sites. Make sure that you have the proper tools available.
  • 24 hours before the storm: Secure your personal dwelling, and make sure you have a plan for pets and loved ones. Secure proper shelter for everyone. Fill vehicle gas tanks, and fill portable gas tanks. Update off-site data backup and secure in a safe location.
  • 12 hours before the storm: Secure buildings, park vehicles in areas where they will not be damaged by flooding or blowing debris, and make any last-minute supply runs for emergency food and water. Have a set or two of dry clothes and shoes in your vehicle (almost nothing is worse than spending 12-24 hours in wet and cold clothes). Coordinate response with other station personnel, prioritize the order of restoration, and coordinate with local authorities on their needs.

A few years ago, I purchased one of these LiPo battery chain saws:

DeWalt battery chain saw

These are great units because you do not have to carry cans of 2-cycle gas around. This model will cut trees 12-14 inches in diameter and I get about 25-35 minutes of cutting time per battery depending on the motor load. I have used it several times to cut small trees from access roads to tower sites.

Above all else, during and after the storm, be safe. Do not take any risks involving downed wires, damaged towers, satellite dishes, etc.

Out with the old, in with the new

Pictures of a backup power systems replacement evolution at one of our clients.  The old generator was a Katolight 45FGH4, circa 1990.  The new generator is a Cummins Power GGHE-1503557 60 KW 3 phase.  Unfortunately, when the Katolight generator was moved from the previous studio location in 1998, it was never installed correctly.  The 500-gallon propane tank was undersized, the gas tubing was undersized, etc.  We fixed those items, but the damage was done.  After running too lean under load a few times, the head gasket blew and there is oil in the antifreeze and antifreeze in the oil.  It is a Ford straight-six engine, and sure, we could rebuild it, but why bother?  This is a major group of stations in a very lucrative market, it makes much more sense to replace the entire unit.

Katolight Genset hooked up to the crane, ready to move
Katolight Genset hooked up to the crane, ready to move
Generator lift
Generator lift

In addition to the head gasket problem, the load on the generator has increased. Since the old generator was installed in 1998, two more stations have been added to this facility. That means another air studio, another production studio, more computers, servers, air conditioning, etc. Thus, the new generator is rated for 60 KW.

Cummins Power Generator delivery
Cummins Power Generator delivery
Cummins generator lift
Cummins generator lift

After the GENSET is placed, connections for remote start, battery charger, block heater, and AC power output are made. We were able to reuse the existing conduit and cable, thankfully the electricians used 3/0 AWG cable for the AC power connections to the transfer switch.

Cummins Power generator in place
Cummins Power generator in place

It appears that they have dropped the Onan name, but not the color, completely.

Troubleshooting the 18 KVA UPS

One of our clients has or rather had a BEST FERUPS 18 KVA UPS. It has stopped working and I was given the following report:

Radio guy: The power went out, the generator started, then I heard a bang.

Myself: You heard a bang?

RG: Yeah, a big BANG!

Myself: You heard a big bang.

And so he did:

Best FERUPS 18 KVA control board.
Best FERUPS 18 KVA control board.
Best FE18KVA control board, MOV destruction
Best FE18KVA control board, MOV destruction

The primary damage is around two MOV’s mounted on the other side of the board. This is the power sense (voltage sample) input to the board. We have attempted to repair it, but alas, it is not repairable. A replacement board runs over $1,400.00 from Eaton Powerware. Since this unit also needs a new set of batteries, it is likely best to replace the entire unit.

Servicing the UPS

A client of ours, WDST in Woodstock, NY, has this Best FE7KVA UPS. This unit is several years old and has already been through a couple of battery replacements.  These are good units, however, Best Power has been bought up by Eaton/Powerware and they are no longer made apparently are still made.

Best Power FE7KVA UPS
Best Power FE7KVA UPS

Regardless of that, the UPS is still functional, but like all UPS’s, it needs battery replacement every so often.  This unit has three battery cases, each holding four 75 Ah (20 hour rate) 12 volt sealed lead acid batteries.  Each battery is slightly larger than an average car battery.  There is one important detail here, the batteries must be gas recombinant because the UPS has a four stage battery charging system.  Gel or AGM batteries will not make it past the first or second equalizing charge.

Best Power FE7KVA individual battery
Best Power FE7KVA individual battery

A bit about batteries and battery charging.  Most battery chargers are three stage units; bulk, absorption, and float.  The rate of charge depends on the voltage of the battery.  Bulk charging sends the most current to the battery and for 12 volt cells, this anything below 12.5 volts or so.  Absorption stage reduces the charging current and supplies a steady current until the battery reaches full charge of 13.8 volts or so.  Float or trickle charging draws very little current, just enough to maintain the battery at full charge.

The forth stage of charging is equalizing which is important for multiple battery series/parallel installations.  This is when the batteries are deliberately overcharged for a period of time.  The reason for equalizing charges is to intentionally boil off some hydrogen gas and knock any sulfur crystals off of the lead plates.  With multiple battery banks in a parallel configuration, it is important to maintain the battery resistances as close as possible so that each bank of batteries is drawn on and charged equally.

In flooded lead acid batteries, this works well and the battery either vents off the hydrogen gas or recombines it will oxygen to make water again.  In non-gas recombinant cells, the hydrogen will be released into the room which may pose an explosion hazard.  Additionally, the electrolyte level will need to be checked after every equalization charge. With a sealed non-recombinant battery, the case my bulge and split, spilling electrolyte and ruining the battery and battery enclosure.  Thus the importance of ordering the correct replacement batteries.

Best Power FE7KVA UPS and battery enclosures
Best Power FE7KVA UPS and battery enclosures

After all, the reason for the UPS is to protect the expensive computer equipment connected to it.  It simply will not do to install the wrong stuff and do more damage than if the UPS did not exist at all.