From: Roger Daugherty at Baldor-Engineering [mailto:RHDaugherty@baldor.com] 

Sent: Monday, March 09, 2009 10:59 AM 

To: Raba, Jim 

Subject: RE: C-face and D-flange mounting motors

And Good Morning to you Jim, 

The definition of “general purpose motor” in NEMA MG1-1.6 (2006-Rev 1) does not contain any 

specified condition with respect to foot-mounted nor footless. Under that definition a “general 

purpose motor” could incorporate C-face or D-flange mounting. 

Yes, C-face or D-flange are two types of mounting that could be used with footless motors. They 

are also two types of mounting that can be used with foot-mounted motors or motors that have 

provisions for foot-mounting. 

When discussing foot-mounted or footless one might consider which element of the structure is 

mounted to a base. A foot-mounted motor attached to a base may have a C-face or D-flange for 

supporting an attachment, such as a gear box or pump. A footless motor may have a C-face or 

D-flange for supporting the motor when mounted to another piece of equipment, such as a gear 

box or pump, that is attached to a base. Likewise, a motor with feet for mounting may have a Cface or D-flange for supporting the motor when mounted to another piece of equipment, such as a 

gear box or pump, that is attached to a base. 

I am not clear why you want to introduce the topics of C-face and D-flange into the topic of 

“footless” versus “foot-mounted” or “having provisions for foot-mounted”. “footless” just means 

that the motor does not have feet nor provisions for feet for mounting. Who cares what the actual 

method of mounting is? 

As for your relating “footless” to EISA: EISA creates its own confusion as to what efficiency 

standard applies to “footless”. As pointed out at the public meeting on January 29, 2009 the way 

in which EISA was written, and was incorporated into the NOPR, created a problem with deleting 

the definition of “electric motor” in EPCA from the definition in EPAct of 1992. Since the EISA 

definition of “general purpose electric motor (subtype I)” makes no distinction with respect to footmounted nor footless the inclusion of “footless” under the topic of “general purpose electric motor 

(subtype II)” is confusing. DOE is faced with the problem of being able to distinguish between 

“general purpose electric motors (subtype I)” and “general purpose electric motors (subtype II)” 

when according to the EISA definition all “general purpose electric motors (subtype II)” appear to 

be “general purpose electric motors (subtype I)”. 

There is only one logical conclusion as to what was actually intended in EISA based on the list of 

seven characteristics supposedly used to identify a motor as a “general purpose electric motor 

(subtype II)”. Each of the seven characteristics is a deviation from one of the characteristics that 

defines an “electric motor” in EPCA as defined in EPAct of 1992 and expanded on in 10 CFR Part 

431: 

(i) U-frame is not T-frame 

(ii) Design C is not Design A or B 

(iii) Definite purpose (per Appendix A to Subpart B) close-coupled pump motor is not a general 

purpose motor 

(iv) Footless motor is not a foot-mounted motor 

(v) Special purpose (per Appendix A to Subpart B) vertical solid shaft normal thrust motor is not a 

general purpose motor 

(vi) 8-pole motor is not a 2, 4, nor 6 pole motor for which efficiency standards were specified in 

EPAct of 1992 

(vii) poly-phase motor with a voltage of not more than 600 volts (other than 230 or 460 volts) is 

not rated at 230/460 volts 

EERE-2007-BT-STD-0007 COMMENT 15
The definition of “general purpose electric motor (subtype II)” obviously relies on the definition of 

“electric motor“ from EPAct of 1992 to have any clear meaning. 

It is only by considering that what the language of EISA should have stated was to retain the 

definition of “electric motor” from EPCA, add “general purpose electric motor (subtype I)” as a 

type of electric motor containing all of the types covered by the standards from EPAct of 1992 

and delineated in Appendix A of Subpart B in 10 CFR Part 431, and add “general purpose electric 

motor (subtype II)” as new types of electric motors that fit the definition of “general purpose 

electric motor (subtype I)” except for 1 feature, such as footless or U-frame. 

It remains unclear as to why DOE can not present a sound decision that the definition of “general 

purpose electric motor (subtype II)” must be built upon the definition of “electric motor” from 

EPAct and that that definition of “electric motor” must then form the basis of the definition of 

“general purpose electric motor (subtype I)”. 

The only hope to get the confusion cleared up appears to be for Congress to pass the proposed 

technical corrections to EISA. If that gets passed it will essentially make the portion of the NOPR 

discussed at the January 29, 2009 public meeting relative to “electric motors” obsolete. 

Roger H. Daugherty, Ph.D

Consulting Engineer

Baldor Electric Company

6040 Ponders Court

Greenville, SC 29615-4617

864.382.2728

864.382.2718 fax

mailto:rhdaugherty@baldor.com

http://www.baldor.com/

From: Raba, Jim [mailto:Jim.Raba@ee.doe.gov] 

Sent: Monday, March 09, 2009 8:21 AM 

To: Roger Daugherty at Baldor-Engineering 

Subject: C-face and D-flange mounting motors

Good morning Roger!

 

Question: Is a C-face mounting or D-flange mounting motor considered a "general purpose 

motor"?

 

Otherwise, I note that section 313(a) of EISA 2007 includes "footless" motors, which I presume 

can be either C- or D- mounting. 

 

Jim

 

James Raba 

Building Technologies Program 

Office of Energy Efficiency & Renewable Energy 

U.S. Department of Energy 

Telephone: (202) 586-8654 

 

EERE-2007-BT-STD-0007 COMMENT 15