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Industry Standards
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toll free 800.334.5214 ACME ELECTRIC |
hubbell-acmeelectric.comUnderwriters’ Laboratories, Inc. is an independent not for profit organization which tests products for safety.
Acme’s transformers are designed and manufactured to comply with UL Standard 506, 1561, 1012, or 1062 and carry the
applicable UL Listing Label. Because of the continuous product evolutions at Acme, it is best that you contact the factory for the
current file and guide numbers associated with the listings.
The Canadian Standards Association is the Canadian counterpart to Underwriters’ Laboratories. Acme’s transformers are also
constructed and rated to comply with CSA Standards C22.2-47 and C22.2-66 and carry the CSA Certification Label.
All of Acme’s transformers are manufactured to meet National Electrical Code requirements.
Other Agencies and Standards:
National Electrical Manufacturers Association (NEMA)
ST-20 1992 (R1978)
American National Standards Institute (ANSI)
OSHA
IEEE
Listed
Certified
B
LOAD
A
SUPPLY
VOLTAGE
OCP LOCATION
How to overcurrent protect (OCP) 600 volt class transformers and associated wiring in accordance with the
‘99 National Electric Code (Articles 450-3(b) and 240-3 (i))
Primary
Secondary
Case
Type of
Supply Voltage
Phase
Number of
Wires on
Secondary
Protection
Required
OCP Location
Current
(amps)
OCP
(% of Rating)
Current
(amps)
OCP
(% of Rating)
1
Main
10
2
Primary Only
A
>9
<9, >2
<2
125
①
167 Maximum
300 Maximum
Not Required
2
Main
10
30
More Than 2
Not Applicable
Primary and
Secondary
②
A and B
>9
<9, >2
<2
125
①
167 Maximum
300 Maximum
>9
<9
125
①
167 Maximum
3
Feeder Circuit
with OCP
10
2
None on Either
—
Not Required
Not Required
4
Feeder Circuit
with OCP
10
30
More Than 2
Not Applicable
Secondary
Only
②
B
Not Required
9
<9
125
①
167 Maximum