The week of Feb 15th was extraordinarily tough here in Houston. As you probably know, we had an unusual cold spell that took the area into single digit temperatures. This caught the state’s electric industry entirely by surprise, taking about 35% of electrical generation offline. So vast tracts of Texas were both cold and without power for several days. Eventually, also without water.
We certainly felt the cold. Our 100 year old Craftsman Cottage was simply not built for this kind of weather. We were fortunate to have gas appliances, including a natural gas-fired fireplace in our living room. We closed of portions of the house to minimize the area we needed to heat. Put an air bed in the living room and did the best we could.
After Hurricane Ike (2008) we were without utility power for about three weeks. This motivated the eventual purchase of a portable generator. We bought it used from a neighbor who was tired of it taking up space in his garage. For several years, it sat idle, occupying a corner in our garage. They’re like that.
This one recent week in February we got to know Genny really well. We came to admire some of her capabilities and a few of her quirks. These lessons are worth sharing.
As you can see, Genny is a Predator (in a nice way) which is a brand sold by Harbor Freight. She’s pretty beefy, rated for 8,750 watts starting load, and 7,000 watts continuous load. That’s not that 14 KW that I had calculated necessary to run out entire household, including central air conditioner, but it’s still quite a lot of power.
Location, Location, Location
I should not need to say this, but I’m going to, just to be safe. Note from the picture above that Genny was located outside, in the driveway, near the garage door. Every year people die from carbon monoxide poisoning from thoughtlessly running a generator indoors. Consider yourself warned.
Further, generators are noisy. So, we seek to place them as far away from our location as practical, given the reality of extension cords.
Finally, under blackout circumstances there is increased likelihood of theft. So, it’s best to keep it well into the property, as out of sight as possible.
The same is true for our cache of gasoline. It’s not safe to store it indoors. It should be outside, but out of sight from the street or sidewalk.
Power to the People
At the outset, we leveraged the two 20 amp circuits made available via US standard plugs. Since we are in the habit of substantial lighting displays at Halloween and Christmas, we had a ready inventory of long extension cords.
In the house we managed to run the following: (in priority order)
- (1) Refrigerator (400 watts)
- (4) Lamps with LED bulbs (36 watts)
- (2) Laptops (150 watts)
- (2) Phone chargers (10 watts)
- Network Core (Switch, Wi-Fi AP) (100 watts)
- A space heater (1500 watts)
- Tivo Roamio Pro (120 watts)
- Vizio M65 TV (200 watts)
- House load = 2,516 watts
The garage apartment (my office) was much simpler.
- A space heater (1500 watts)
- Network core (cable modem, switch, misc. minor stuff) (150 watts)
- Garage load = 1,650 watts
The total load on Genny was about 4,200 watts, so around 60% of rated capacity. To carry that load it burned 5 gallons of gas every 10 hours.
A single 120V 20A circuit can deliver 2,400 watts. However, that requires a VERY heavy duty extension cord…which I did not have. So, I had to run two, medium duty extension cords into the house. I also made sure that the space heater was the only load on one of them.
Genny has a third 20A circuit that’s available by way of a heavy duty twist-lock connector. A quick trip to a local hardware store provided the parts necessary to use this, too. That allowed load distribution safely and reliably across three 20A circuits.
UPS vs Outlet Strips
In both the office and the house, the network core is powered via a UPS. These are not large models since they’re really only intended to sustain the small load through momentary outages, typical of utility line switching. I’m happy that they can run the core switch, APs, phones and such for 15 minutes.
I am on a budget, so the UPSs that we have are inexpensive, “line interactive” models. They ride in parallel to the utility power, to augment it when needed. They do not fully buffer the load from the utility power.
I very quickly learned that line interactive UPSs don’t appreciate the uneven power from a generator. Continuous voltage fluctuations (instability) caused the UPSs to cycle in/out of service every few seconds. Dismayed, I had to take both UPSs offline, replacing them with simple outlet strips.
I have resolved to keep my eye out for a bargain on some dual-conversion (aka online) UPSs. These are a more sophisticated design that convert the incoming power to DC then recreate clean, sine-wave power for the load. They fully isolate the load from the vagaries of the incoming power. This is much better for powering sensitive electronics.
Furnace vs Space Heater
In the garage there is no built-in furnace. As we don’t have much cold each year, I’ve always used a simple space heater when necessary. During this recent and coldest of weeks, I only needed to keep the office above freezing. The space heater was sufficient, if not very efficient.
The house is different matter entirely. It makes no sense to run a small space heater when we have a gas-fired furnace that was brand new in 2018. The furnace is an American Standard Platinum model that draws less power than a space heater. So, I rigged the furnace to connect to generator power.
The combination of the furnace and the fireplace kept the living room comfortable, and the rest of the house a passably warm 55-60F. The furnace ran this way for several hours.
Then the furnace just stopped. A quick look inside the furnace revealed that it was trying to start, but for some reason could not.
There was nothing I could do about that. So, we reverted to the space heater. And closed off that part of the house that could not be heated. Towels under doors sealed gaps to keep the cold out.
I initially feared that the furnace had been damaged by uneven generator power. However, when utility power eventually returned the furnace once again ran normally. This leads me to infer that, like the UPSs, it did not like the uneven power provided by the generator.
Had the furnace been a simpler model it might have been less sensitive to powerline irregularity. The “platinum” model that we selected includes an electronically controlled blower, which will eventually be required when we upgrade the existing air conditioner to a two-stage or variable-speed model.
It’s curious, and rather unexpected, that the furnace was impacted in a manner similar to the UPSs.
Generator vs Invertor
Genny is a largish, portable generator. We bought it rather impulsively, since the neighbor wanted to sell it. We paid about half of what it would cost new. It’s loud, but in the recent case it got the job done.
Had I been more strategic I might have considered buying an “Invertor.” This is like a generator, but includes a more sophisticated design that ensures smooth, clean power for sensitive electronic devices. Invertors tend to be smaller (less wattage) and quieter. Also, substantially more costly.
An invertor is very similar in principle to dual-conversion UPS. So, I guess my next step is to save up some $ to replace our existing, admittedly cheap, UPSs with Karl Fife approved* approved dual-conversion models. That’s probably more practical than installing a standby generator, which looks to be a $12k project.
Some years back the main water feed from the city broke, forcing us to have it replaced. This turned out to be a blessing. In this extreme cold our water feed never froze up. We had water to the outside taps in our front garden all the time, even letting some neighbors draw water into containers.
An earlier freeze scare has inspired me to wrap the older pipes under the house with insulation. Those running across the underside of the house did not freeze.
Some smaller pipes feeding up into the house did freeze, but none were damaged. In fact, we never lost a functional bathroom in the house.
We were pretty fortunate in this case. We had plenty of supplies. It was strange and stressful. Ultimately, we were merely inconvenienced for about a week.
*Some years ago during a VUC call Karl made a compelling case for online UPS.