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[GMCnet] Soft start the for AC [message #327435] Sat, 23 December 2017 11:56 Go to next message
glwgmc is currently offline  glwgmc   United States
Messages: 1014
Registered: June 2004
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Senior Member
Likely would be, Scott. At least my dust collector with the VFD soft start is much quieter coming on than the same DC without frequency controlled soft start. The 220vac Mechanical soft start units employed by Felder (very high quality Clean Tech dust collectors that are way more effective than any of the cyclone or puff bag units) were a mess of relays, timers, capacitors and a second set of windings inside the motor. The motor would start on one set of windings, spin for a timer defined amount of time before a large three connector relay would switch the unit over to the normal set of windings. Very expensive way to do what can be done easily with modern VFDs. Plus they would have been able to sell,the same unit around the world and let the VFD take care of the 50hz vs 60hz issues.

The old original AC on our 78 Royale would shake the coach violently and groan loudly on startup. No sleeping through that! I replaced it with a Carrier unit (while Carrier was still making RV AC units) and it made far less noise on startup. If I had known then about the 120vac soft start units I would have tried it on the original unit which still cooled well. If anyone wants the original unit it is up on the rafters in the GMC garage. You are welcome to come get it. It was easier to stash it there while removing it from the top of the GMC than it was to figure out how to get it down onto the ground!

Jerry

Jerry Work
The Dovetail Joint
Fine furniture designed & hand crafted
in the 1907 former Masonic Temple building
in historic Kerby, OR
http://jerrywork.com
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Date: Sat, 23 Dec 2017 09:23:28 -0700
From: Scott Nutter
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Soft start for AC
Message-ID:
Content-Type: text/plain; charset="utf-8"

With a soft start installed, would the noise level of the compressor on start up be less than without the soft start?

Might be good for AC's installed in the bedroom if it is quieter. I know the low profile Coleman's can be a little noisy on compressor startup.
Scott
--
Scott Nutter
1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, tankless water heater, everything Lenzi.
Houston, Texas
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Jerry & Sharon Work
78 Royale
Kerby, OR
Re: [GMCnet] Soft start the for AC [message #327440 is a reply to message #327435] Sat, 23 December 2017 18:23 Go to previous message
Scott Nutter is currently offline  Scott Nutter   United States
Messages: 781
Registered: January 2015
Location: Houston/San Diego
Karma: 4
Senior Member
Jerry,
I'm assuming your old factory rear AC was 11,000 btu? I believe my old AC was the same.
I put a Coleman mach 8 15,000 btu in the rear. Great AC but too much btu's for such a small area, it constantatly short cycles. I guess the engineers were right in the first place!

So the delima is,
1. Replace my 15k mach 8 low profile for a 11k mach 1 standard height. Cost would be around $600.
2. Get the soft start for the mach 8 (but that still won't stop the short cycling). Cost $300

Coleman does make a 9,000 btu mach 8 low profile unit. Maybe that's the way to go..............but I can't find anyone who has one for a review....

Scott.


Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas
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