The International Cessna 170 Association

Has anyone received approval to install the Zeftronics G1200N regulator on their 170?

https://www.zeftronics.com/shop/g1200n/

I need a new regulator and was thinking about going the solid state route. I called Zeftronics and the G1200N is the replacement for the Delco 1118736 that I have. However, they do not list the 170 as an approved aircraft. They said I would need field approval.

Their 35A version is approved for the 170 series, and their literature declares it to be a replacement for the Delco-Remy vibrating points regulator which is approved for the 170 series. I think a letter from them to their FSDO should get that quickly approved, but lacking that, a letter from them assuring you of that matter should pave the road for you with FAA.

It's unknown at the moment how the most recent change has affected Field Approvals since FSDO's have been closed.

Interesting that the 35A version lists the 170 but the 20A version does not. I just bought new 20A generator at OH and would like to stick with it for now.

I'm wondering if the only difference is the calibration... if so, I wonder if they'd "calibrate" a 35A down to 20A for you.... (You could then placard it.)

(You can always install a higher rated gen with a smaller rated regulator without harm. The only problem being that all the regulator will ever request will be the lesser of the two. However, NEVER install a lower rated generator with a higher rated regulator as the higher request from the reg will over-work/burn up the lower rated gen.)

Strange that they approved the 172 thru 172H which also have O-300s with 20A generators and not the the 170. However, I would think this would make is very easy to get a field approval.

I'll talk to my IA about it on Monday but I don't see it as too much of a problem. Field approvals are getting harder to get in lieu of using the 337. I think if we write it up on a 337 with the supporting documentation it will probably get approved. Do they even look at 337's nowadays? They all get sent off to OK City into he big black hole never to be heard from again.

Which begs the question. Once the IA signs the logs and 337, isn't it official? The 337 copy gets sent in but by the time the FAA gets it the customer is long gone.... I always wondered about that.

lowNslow wrote:Strange that they approved the 172 thru 172H which also have O-300s with 20A generators and not the the 170. However, I would think this would make is very easy to get a field approval.

Agreed. (An Autozone replacement under AC 23-27 (Wells-Brand, PN: VR699 $60) 35A vibrating points regulator I know of is now in it's 12th year without any troubles at all. It's a replacement for it's identical predecessor which got burned up in an ill-advised condenser-addition suggested by an avionics shop. It was orig purchased w/lifetime warranty so it's replacement was simple. Units purchased new now have 1 yr.)

NAPA PN: ECH VR126 is ten dollars less.

nippaero wrote:I'll talk to my IA about it on Monday but I don't see it as too much of a problem. Field approvals are getting harder to get in lieu of using the 337. I think if we write it up on a 337 with the supporting documentation it will probably get approved. Do they even look at 337's nowadays? They all get sent off to OK City into he big black hole never to be heard from again.

Which begs the question. Once the IA signs the logs and 337, isn't it official? The 337 copy gets sent in but by the time the FAA gets it the customer is long gone.... I always wondered about that.

If a Form 337 is completed/submitted to document major repairs (such as a ground loop repair) using acceptable methods (AC43.13) then no response is required from FAA and the document is filed under the aircraft's records. This would be done when the repairman knows the repair is acceptable.

But if a regulator for a Mitzubishi is installed in an airplane for which is is not approved (it doesn't meet the rule) it is not simply mailed to OKC for recordation...it is submitted for approval in Block 3 of the Form 337 to an Airworthiness Inspector. In such case, no approval for return to service is appropriate until the Block 3 approval is rec'd in return.

George, I actually went down to NAPA and purchased a VR126 yesterday. It works beautifully for "ground testing" and I used it to validate that my old Delco was bad.


Thanks for explaining the 337 process. I thought the local FSDO used to approve the 337's and now they are all mailed to OK City? I wonder how long that approval process takes?

nippaero wrote:George, I actually went down to NAPA and purchased a VR126 yesterday. It works beautifully for "ground testing" and I used it to validate that my old Delco was bad.

Be careful not to get confused and install the original DR cover onto the Echlin regulator or you may forget and the average inspector will not catch the error for decades. Then you'll have to document it under AC23-27.

Actually, the cover from my DR unit will not fit on the one I got from NAPA. There is a difference in how they covers fit. At least on the one I received. I'll try to get a picture later.

Hmmmn... I didn't know that. The Autozone one is an exact fit. Oh well. Thanks for the info.

Actually, the one I got was the VR122. Do yo know what the difference is between the VR122 and the VR126? I think the VR122 was mentioned in a old thread.

EDIT: Nevermind. I think the VR122 is the 20Amp model.....
If you look at the picture in this link, you'll see that the cover is held on with two small screws that are fastened on the outside of the cover. My original DR has two long screws not the top of the cover.

https://www.napaonline.com/en/p/ECHVR122

nippaero wrote:Actually, the one I got was the VR122. Do yo know what the difference is between the VR122 and the VR126? I think the VR122 was mentioned in a old thread.

EDIT: Nevermind. I think the VR122 is the 20Amp model.....
If you look at the picture in this link, you'll see that the cover is held on with two small screws that are fastened on the outside of the cover. My original DR has two long screws not the top of the cover.

https://www.napaonline.com/en/p/ECHVR122

The VR122 is a 12V 27A regulator (suitable for a 25A gen.) A VR123 is a 12V 22A regulator (suitable for a 20A gen.) The VR126 is a 12V 35A reg. A VR125 is a 12V 50A reg. (All according to my copy of the NAPA/Echlin Illustrated Parts Guide and Specification Charts.

Do you have a pic of your "orig DR"? Does it have a DR part number on it? The original Delco Remy 20A regulator was PN1116736 (later renumbered to VR300-14-20)

I was looking at the info in this thread http://www.cessna170.org/forums/viewtop ... 931#p68931

It's a 1118736.