I am concerned that I may have had my builder's electrician suggest and acquire a whole house backup generator that may not work with my geo heat pump. What information can I provide that may assist someone in letting me know if what has been acquired will work?
LRA Locked rotor amps = the startup amp draw. Just googled and found some charts - SIZING A GENERATOR FOR ELECTRIC MOTOR LOADS
Attached is a pdf that Water Furnace (WF) posted a while back. Their Intellistart (soft-start) significantly lowers LRA on the WF systems listed. I can't say what effect their Intellistart would have on a non-WF unit, or if it would effect the warranty on a non-WF unit. However, you may be able find a compatible soft-start unit for your system. You would obviously need to reference the specs on the unit you choose.
Emerson Climate Technologies ( manufacturer of Copeland Compressors) marketed SecureStart last summer. It is a device similar to Waterfurnace’s Intellistart for use with Copeland single phase compressors. The company suggests it lowers a compressor’s starting current by up to 75%. Regards, Masoud
Gotta love the marketing "up to" 75%. A more reliable # for sizing would be 60% - and that's substantial. FYI - The "softstart" was pioneered in Australia where they are mandatory to meet peak demand load requirements.
when completing utility forms we do not suggest softstart kits reduce lra by more than 50%. stakes are to high if we are wrong. j
One also doesn't want to be on the ragged edge in genny sizing - tis far better to do without the load in question than to force feed it with a marginal generator. Neither the load nor the genny will last long in a bad marriage. I start my Envision 038 with a 24 kW Guardian, without a soft start, but the Guardian engine at 2.4 liters out-displaces my car engine at 1.9...
yup I'm watercop over at tdiclub, though I spend little time there any more...I thought your name was vaguely familiar. 263k miles on the Jetta and counting, 55-59 mpg. It used to routinely break 60 but the underbelly cover fell apart so I yanked it, which may have messed up the aerodynamics.
WATERCOP?!?! I remember you totally rocking the mpg competitions a couple years ago. I traded mine in july with 203k on the clock. 2007 MINI in the stable now. OK. Done hijacking. (I have a panzer plate with no hardware if you're interested. you can have it for the cost of shipping. )
MD Check you PM - you have mail. OP - apologies for the brief hijack - write if you have more genny questions
I would be cautious about using a soft start. Maybe OK if it was designed by the system or motor OEM. But an aftermarket add-on is really rolling the dice. If the motor is ECM (electronically commutated motor) you might not need to worry about it since the electronic brains help reduce LRA.
SecureStart / IntelliStart (probably same guts or nearly so) are intended specifically for Copeland Scrolls. Emerson owns Copeland, so the relationship is OK.
Truth be told they are all "aftermarket" as they are not installed by Copeland. Watch warranties and monitor equipment whenever generators run. Purchasing enough generator to start geo without "soft-start" may cost little more for H/Ps under 5 ton. j
I still gotta figure that a soft start sanctioned by Copeland / WF / CM is probably safe and having it on a system to be started by any generator reasonably feasible for a single house would be good for everything involved. In fact I wonder if all systems would be served well by a softstart - reduced inrush and starting torque sound good electrically and mechanically. I may try one.
Sometime in the past 2 yeaars, WF started offering Intellistart as a factory option on Envision systems, so it's clearly warranty-friendly. If it had been available two years ago, it would have been a no-brainer to include it. I suspect that most units are now being shipped with Intellistart.
