To sort of offset the previous post; not all is bad. We have been able to install some backup power solutions before winter. The best part, we got this work done before the temperatures moved to the negative digits.
The 18 KVA UPS:
Eaton Powerware 9170+ 18 KVA UPS
I like this unit. It is completely modular, with removable battery packs and hot plugable power modules, this thing looks pretty bullet proof. Here it is with the covers off:
Eaton Powerware 9170+ 18 KVA UPS covers off
The top six positions are power modules, each one handles 3 KVA. The bottom are the battery packs. Right now the load is about 6.5 KW and the run time is 18 minutes. Mounted on the wall to the right, a make before break bypass switch and a 25 KVA dry core isolation transformer.
Another generator replacement:
The old and slightly long at the tooth Generac genset being hauled away.
Old generator, off to generator heaven
New Cummins Power GGHE-1515890 60 KW propane genset, test under load:
Cummins power generator, test with 35% load
With gas powered generators, it is fine to break them in with fairly light loads. I think the maximum load this unit will see with current transmitter equipment is 60%, and that is if all AC units are running, the main transmitter, the HD transmitter and the backup transmitter being tested into the load.
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
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 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
It appears that they have dropped the Onan name, but not the color, completely.
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 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.
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
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
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
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.