International Standards and Conformity Assessment for all electrical, electronic and related technologies



Reference EN 60255-149:2013
Title Measuring relays and protection equipment - Part 149: Functional requirements for thermal electrical relays
Project Number 24235
Abstract/Scope IEC 60255-149:2013 specifies minimum requirements for thermal protection relays. This standard includes specification of the protection function, measurement characteristics and test methodologies. The object is to establish a common and reproducible reference for evaluating dependent time relays which protect equipment from thermal damage by measuring a.c. current flowing through the equipment. Complementary input energizing quantities such as ambient, coolant, top oil and winding temperature may be applicable for the thermal protection specification set forth in this standard. This standard covers protection relays based on a thermal model with memory function.


Current Stage code 6060
Current Stage code date 2013-10-04
Current Stage code deadline 2014-06-03
Deadline date for vote  


Order Voucher  


IEC Technical Body IEC/TC 95
Reference Document IEC 60255-149:2013 (EQV)
ICS 29.120.70 - Relays
Keywords Relays; Protection; Requirements; Thermal
Note Supersedes EN 60255-8:1998 * 2013-08-13 - Publication allocated to
Special National Condition(s)  


Categories - Aspects
Product Life Cycle


Deadline Date
6060 2013-10-04 2014-06-03 export to doc file  EN  FR  DE
5099 2013-09-03 2013-10-01  
5060 2013-07-09 2013-07-30 export to doc file  EN
5020 2013-05-03 2013-07-05  
3090 2013-04-30 2013-05-03  
5060 2012-10-29 2012-11-19 export to doc file  EN
5020 2012-05-25 2012-10-26  
1090 2012-05-22 2012-05-25  

Implementation Dates

date of Ratification (DOR) (1) 2013-09-03
date of Availability (DAV) (2) 2013-10-04
date of Announcement (DOA) (3) 2013-12-03
date of Publication (DOP) (4) 2014-06-03
date of Withdrawal (DOW) (5) 2016-09-03


Supersedes EN 60255-8:1998
Superseded by  
Normative reference (6) IEC 60050 series
EN 60085
EN 60255-1
EN 61850-7-4

(1) Date of ratification (dor) date when the Technical Board notes the approval of an EN (and HD for CENELEC), from which time the standard may be said to be approved

(2) Date of availability (dav) date when the definitive text in the official language versions of an approved CEN/CENELEC publication is distributed by the Central Secretariat

(3) Date of announcement (doa) latest date by which the existence of an EN (and HD for CENELEC), a TS or a CWA has to be announced at national level

(4) Date of publication (dop) latest date by which an EN has to be implemented at national level by publication of an identical national standard or by endorsement

(5) Date of withdrawal (dow) latest date by which national standards conflicting with an EN (and HD for CENELEC) have to be withdrawn

(6) This list of normative references is purely indicative. The only official list of normative reference is the list of the published standard.