I know we’ve talked about having backup power available for various things, and I’m wondering whether there’s a significant benefit to having a pure sine wave vs. a modified sine wave for doing things like charging devices, running computers, etc.
Basically looking at something that could provide emergency power for some tech, run a small chest freezer if there was an extended outage, etc. And “pure” is significantly more expensive than modified.
Anybody have any thoughts?
There are a couple of different time spans here.
Catch power dips. Time to shutdown computers, charge phones if an extended outage. This is ups territory.
If well stocked, your freezer should be good for a day or two with no/limited opening. Beyond that, you’re looking at deep-cycle batteries and an inverter, or a small generator. I bought a duel-fuel generator that can run on propane so I don’t have to worry about gasoline sitting around and going bad, and for safety. Also a consideration if you have refrigerated medications.
Can’t really speak to this, other than to say I have this CyberPower (simulated sine) and it gives me about 6-8 minutes to power down my iMac Pro, 2 monitors, half dozen external drives, Synology NAS, cable modem, and Synology router.
Most of the things you want to run off a UPS are fine with modern modified sine waves. Certain types of motors and resistance circuits don’t like it.
I have multiple UPSs on computer equipment and a backup generator. The UPSs handle the outage until the generator kicks in. Recent storm knocked power out for 3 hours and all worked well.
Yeah - I’m looking at this category, with enough power to keep phones topped off, the chest freezer / fridge running, etc. And output would need to be high enough to catch the initial surge load from the compressor in the chest freezer / fridge.
Since we’re in an apartment, I was looking at 1 or 2 large deep-cycles and a 1500W inverter (again, surge load) from someplace like Harbor Freight or Amazon. Getting a pure sine wave would almost double the inverter cost, hence the question.
Any experience running a fridge/freezer on a modified sine?
What kind of computer(s)? I went with sine based on this information as I have an iMac.
I think motors are more efficient on sine waves, which would increase battery run time. I don’t use a UPS for anything motorized, though, so I have looked into this minimally.
As for the freezer, you can keep things frozen during a short term power loss if you leave the door shut. Food will stay frozen for days if the freezer is well stocked with frozen food/blocks of ice (field tested by a family member during a multi-day unplanned/unexpected power outage). One strategy is to keep bottles of frozen water in the freezer when it begins to empty of food. Barring a catastrophic regional power outage, you can also just buy bags of ice to pop in the freezer if your neighbourhood is experiencing an extended power loss. I suspect this method will preserve your food for longer than an affordable UPS could.
I should also add that I occasionally get too excited about deals at Costco and buy more food than can fit in my fridge (I can’t say no to a big bag or three of Koru apples!). I put the extra food (not meat) in a cooler with an ice pack. The food can keep least a week in there easily. I’d use the same strategy during a long power outage: I’d put a bunch of ice in the fridge and keep it closed as much as possible. In a pinch I’d sacrifice bags of frozen veg to keep the fridge cold. You can used the thawed veg to make soup stock after, so no waste.
Yes, I have a MSW inverter in my motorhome and it runs a KitchenAid reefer, an induction cooktop, and a microwave. The microwave doesn’t produce as much output so it takes about 20% longer cook time. TVs, satellite receiver, usb chargers all work fine.