427:
1232:
1790:
1096:
1825:
1813:
1801:
1108:
100:
The closed doors may or may not mechanically latch or lock in the closed position. Many fire doors do not lock, to allow building occupants to move within the building to find an exit easily. On the other hand, security doors may close, latch, and lock, to prevent passage. Other designs are used to
70:, usually attached to a wall or mounted in a floor pedestal enclosure, next to the door it controls. The mechanism may be mounted near the floor, at the upper corner of the open door, or at any convenient height along the latch edge (away from the hinged edge).
81:
joint, is attached to the door so that it can contact the electromagnet when the door is fully opened. An electric current typically energizes the electromagnet to attract and hold the steel plate, keeping the door open. Unlike
93:, or similar emergency system is triggered, it will cut electrical power to the electromagnetic door holders under its control. The door holders release, allowing the doors to close automatically using
120:, which could cause the electromagnet to fail to release, some door holders are equipped with a spring-loaded pin that helps push the magnetic plate away from the electromagnet when the power is cut.
109:
In life safety and security applications, electromagnetic door holders must be very reliable; the simplicity of the mechanisms helps considerably. They are designed to be
943:
86:, the magnetic attraction of an electromagnetic door holder is usually weak enough that it can be manually overpowered at any time by anyone, allowing door to close.
738:
931:
113:
in that anything interfering with their operation (such as a power failure) will cause them to release the doors and allow them to close.
546:
1816:
236:
264:
910:
1146:
955:
949:
101:
secure sliding or overhead doors similarly, holding them open until a signal to release the doors to close automatically.
451:
826:
1111:
587:
275:
1735:
97:. The electric power to keep the doors open is typically 12 VDC, 24 VDC (common), 24 VAC, 120 VAC, or 240 VAC.
1669:
937:
894:
566:
229:
1055:
1648:
1395:
1008:
846:
1750:
1124:
879:
811:
461:
90:
1139:
446:
386:
1608:
961:
796:
456:
1492:
1405:
1099:
905:
821:
801:
778:
541:
306:
222:
55:
1850:
1709:
1663:
1593:
1390:
748:
713:
561:
511:
1765:
1281:
889:
768:
743:
733:
441:
401:
154:
16:
This article is about a mechanism to hold a door open. For the magnetic locking mechanism, see
1770:
1804:
1793:
1704:
1537:
1132:
1076:
1050:
1003:
618:
506:
486:
1674:
1628:
1565:
1527:
1426:
1298:
1251:
773:
633:
341:
83:
17:
8:
1623:
1532:
1467:
1375:
1303:
816:
723:
1828:
1824:
182:
1855:
1410:
1370:
603:
531:
496:
491:
346:
117:
1231:
1745:
1472:
1365:
1216:
1029:
1024:
1019:
915:
806:
788:
678:
516:
426:
411:
47:
1658:
1517:
1385:
1360:
1013:
351:
1755:
1719:
1684:
1653:
1436:
1431:
1196:
708:
643:
582:
551:
526:
476:
471:
285:
245:
129:
1714:
1689:
1580:
1522:
1186:
1181:
1167:
874:
851:
836:
698:
638:
608:
577:
521:
481:
416:
406:
301:
134:
1844:
1633:
1613:
1246:
1206:
1201:
1081:
1071:
869:
841:
758:
376:
366:
336:
280:
67:
1679:
1588:
1555:
1547:
1507:
1457:
1441:
1334:
1286:
1266:
1163:
1159:
1155:
998:
884:
763:
753:
688:
653:
613:
572:
536:
326:
321:
291:
1154:
1775:
1760:
1694:
1603:
1512:
1462:
1355:
1191:
718:
673:
663:
556:
501:
466:
361:
94:
58:
or a similar emergency control system usually controls the door holder.
1638:
1487:
1319:
978:
831:
331:
316:
296:
74:
1618:
1598:
1560:
1482:
1477:
1400:
1339:
1256:
900:
728:
693:
683:
668:
648:
623:
396:
391:
356:
311:
259:
110:
51:
1699:
1570:
1497:
1329:
1291:
1261:
1221:
1211:
993:
703:
658:
381:
371:
270:
214:
1380:
1324:
1276:
1271:
1643:
78:
1502:
1034:
988:
983:
944:
National
Council of Examiners for Engineering and Surveying
209:
66:
A simple electromagnetic door holder consists of a strong
54:
or security door open until given a signal to release. A
23:
Electromechanical latch used in fire and security systems
739:Penetrant (mechanical, electrical, or structural)
1842:
155:"Need-To-Know Basics of Commercial Door Holders"
1140:
230:
1147:
1133:
547:Hypoxic air technology for fire prevention
237:
223:
932:Fire Equipment Manufacturers' Association
265:Boiling liquid expanding vapor explosion
911:Listing and approval use and compliance
32:electromagnetic door holder and release
1843:
177:
175:
50:mechanism which can be used to hold a
1128:
956:Society of Fire Protection Engineers
218:
147:
1812:
1800:
1107:
950:National Fire Protection Association
244:
172:
13:
452:Condensed aerosol fire suppression
73:A steel plate, often mounted on a
14:
1867:
827:Fire alarm notification appliance
203:
1823:
1811:
1799:
1789:
1788:
1230:
1106:
1095:
1094:
425:
38:, sometimes informally called a
588:Vehicle fire suppression system
276:Combustibility and flammability
159:Beacon Commercial Door and Lock
89:If a fire alarm control panel,
1736:Glossary of locksmithing terms
104:
1:
1670:Perimeter intrusion detection
938:Institution of Fire Engineers
895:Fire Safety Evaluation System
567:Personal protective equipment
140:
1649:Miniature snap-action switch
1396:Time-delay combination locks
1009:GHS precautionary statements
847:Manual fire alarm activation
61:
7:
1751:John M. Mossman Lock Museum
1741:Electromagnetic door holder
880:Fire protection engineering
812:Explosive gas leak detector
629:Electromagnetic door holder
462:External water spray system
123:
91:burglar alarm control panel
28:electromagnetic door holder
10:
1872:
1056:Harry C. Bigglestone Award
447:Automatic fire suppression
387:K-factor (fire protection)
15:
1784:
1728:
1609:Closed-circuit television
1579:
1546:
1450:
1419:
1348:
1312:
1239:
1228:
1174:
1090:
1064:
1043:
971:
962:Underwriters Laboratories
924:
860:
797:Aspirating smoke detector
787:
596:
457:Detonation flame arrester
434:
423:
252:
1493:Kensington Security Slot
1406:Tubular pin tumbler lock
906:Kitchen exhaust cleaning
822:Fire alarm control panel
802:Carbon monoxide detector
779:Standpipe (firefighting)
542:Gaseous fire suppression
307:Enthalpy of vaporization
56:fire alarm control panel
1710:Vandal-resistant switch
1664:Passive infrared sensor
1594:Alarm monitoring center
1391:Rotary combination lock
1240:Components and hardware
749:Pressurisation ductwork
714:Firewall (construction)
562:Passive fire protection
512:Fire suppression system
1766:Lock Museum of America
1282:Bored cylindrical lock
925:Industry organizations
890:Fire-resistance rating
769:Smoke exhaust ductwork
744:Penetration (firestop)
734:Packing (firestopping)
442:Active fire protection
402:Spontaneous combustion
1794:Category:Locksmithing
1705:Ultrasonic transducer
1077:Template:Firefighting
1051:Arthur B. Guise Medal
1004:GHS hazard statements
507:Fire sprinkler system
487:Fire-retardant fabric
116:To overcome possible
84:electromagnetic locks
1675:Photoelectric sensor
1629:Glass break detector
1528:Real-estate lock box
1427:Electromagnetic lock
1299:Single-point locking
1252:Interchangeable core
1175:Fundamental concepts
861:Professions, trades,
774:Smokeproof enclosure
634:Electromagnetic lock
342:Flammability diagram
253:Fundamental concepts
161:. Beacon Metals, Inc
18:Electromagnetic lock
1771:Musée de la Serrure
1624:Fingerprint scanner
1533:Steering-wheel lock
1468:Chubb detector lock
1376:Magnetic keyed lock
1304:Three-point locking
817:Fire alarm call box
724:Heat and smoke vent
187:Designing Buildings
1411:Wafer tumbler lock
1371:Lever tumbler lock
789:Fire alarm systems
604:Annulus (firestop)
532:Flashback arrestor
497:Fire-safe polymers
492:Fire retardant gel
347:Flammability limit
183:"Hold-open device"
118:remanent magnetism
1838:
1837:
1746:Exit control lock
1473:Child safety lock
1366:Disc tumbler lock
1217:Physical security
1122:
1121:
1030:Safety data sheet
1025:List of S-phrases
1020:List of R-phrases
916:Sprinkler fitting
807:Circuit integrity
679:Fire extinguisher
517:Firefighting foam
412:Thermal radiation
48:electromechanical
44:electric doorstop
1863:
1827:
1815:
1814:
1803:
1802:
1792:
1791:
1659:Occupancy sensor
1518:Power door locks
1451:Other lock types
1420:Electronic locks
1386:Combination lock
1361:Pin tumbler lock
1349:Mechanical locks
1234:
1149:
1142:
1135:
1126:
1125:
1110:
1109:
1098:
1097:
1014:Life Safety Code
619:Compartmentation
429:
352:Flammable liquid
239:
232:
225:
216:
215:
197:
196:
194:
193:
179:
170:
169:
167:
166:
151:
36:hold-open device
1871:
1870:
1866:
1865:
1864:
1862:
1861:
1860:
1841:
1840:
1839:
1834:
1780:
1756:Key to the City
1724:
1720:Window security
1685:Pressure switch
1654:Motion detector
1581:Security alarms
1575:
1542:
1446:
1437:Electric strike
1432:Electronic lock
1415:
1344:
1308:
1235:
1226:
1197:Key duplication
1170:
1168:security alarms
1153:
1123:
1118:
1086:
1060:
1039:
967:
920:
862:
856:
783:
709:Firestop pillow
644:Emergency light
597:Building design
592:
583:Tank blanketing
552:Inerting system
527:Flame retardant
477:Fire protection
472:Fire prevention
430:
421:
286:Dangerous goods
248:
246:Fire protection
243:
206:
201:
200:
191:
189:
181:
180:
173:
164:
162:
153:
152:
148:
143:
130:Electric strike
126:
107:
64:
24:
21:
12:
11:
5:
1869:
1859:
1858:
1853:
1851:Door furniture
1836:
1835:
1833:
1832:
1820:
1808:
1796:
1785:
1782:
1781:
1779:
1778:
1773:
1768:
1763:
1758:
1753:
1748:
1743:
1738:
1732:
1730:
1726:
1725:
1723:
1722:
1717:
1715:Water detector
1712:
1707:
1702:
1697:
1692:
1690:Proximity card
1687:
1682:
1677:
1672:
1667:
1661:
1656:
1651:
1646:
1641:
1636:
1631:
1626:
1621:
1616:
1611:
1606:
1601:
1596:
1591:
1585:
1583:
1577:
1576:
1574:
1573:
1568:
1563:
1558:
1552:
1550:
1544:
1543:
1541:
1540:
1535:
1530:
1525:
1523:Protector lock
1520:
1515:
1510:
1505:
1500:
1495:
1490:
1485:
1480:
1475:
1470:
1465:
1460:
1454:
1452:
1448:
1447:
1445:
1444:
1439:
1434:
1429:
1423:
1421:
1417:
1416:
1414:
1413:
1408:
1403:
1398:
1393:
1388:
1383:
1378:
1373:
1368:
1363:
1358:
1352:
1350:
1346:
1345:
1343:
1342:
1337:
1332:
1327:
1322:
1316:
1314:
1310:
1309:
1307:
1306:
1301:
1296:
1295:
1294:
1289:
1284:
1274:
1269:
1264:
1259:
1254:
1249:
1243:
1241:
1237:
1236:
1229:
1227:
1225:
1224:
1219:
1214:
1209:
1204:
1199:
1194:
1189:
1187:Authentication
1184:
1182:Access control
1178:
1176:
1172:
1171:
1152:
1151:
1144:
1137:
1129:
1120:
1119:
1117:
1116:
1104:
1091:
1088:
1087:
1085:
1084:
1079:
1074:
1068:
1066:
1062:
1061:
1059:
1058:
1053:
1047:
1045:
1041:
1040:
1038:
1037:
1032:
1027:
1022:
1017:
1011:
1006:
1001:
996:
991:
986:
981:
975:
973:
969:
968:
966:
965:
959:
953:
947:
941:
935:
928:
926:
922:
921:
919:
918:
913:
908:
903:
898:
892:
887:
882:
877:
875:Fire insurance
872:
866:
864:
858:
857:
855:
854:
852:Smoke detector
849:
844:
839:
837:Flame detector
834:
829:
824:
819:
814:
809:
804:
799:
793:
791:
785:
784:
782:
781:
776:
771:
766:
761:
756:
751:
746:
741:
736:
731:
726:
721:
716:
711:
706:
701:
699:Fire sprinkler
696:
691:
686:
681:
676:
671:
666:
661:
656:
651:
646:
641:
639:Emergency exit
636:
631:
626:
621:
616:
611:
609:Area of refuge
606:
600:
598:
594:
593:
591:
590:
585:
580:
578:Spark arrestor
575:
570:
564:
559:
554:
549:
544:
539:
534:
529:
524:
522:Flame arrester
519:
514:
509:
504:
499:
494:
489:
484:
482:Fire retardant
479:
474:
469:
464:
459:
454:
449:
444:
438:
436:
432:
431:
424:
422:
420:
419:
417:Water pressure
414:
409:
407:Structure fire
404:
399:
394:
389:
384:
379:
374:
369:
364:
359:
354:
349:
344:
339:
334:
329:
324:
319:
314:
309:
304:
302:Dust explosion
299:
294:
289:
283:
278:
273:
268:
262:
256:
254:
250:
249:
242:
241:
234:
227:
219:
213:
212:
210:Exterior Doors
205:
204:External links
202:
199:
198:
171:
145:
144:
142:
139:
138:
137:
135:Smart doorbell
132:
125:
122:
106:
103:
63:
60:
46:) is a simple
22:
9:
6:
4:
3:
2:
1868:
1857:
1854:
1852:
1849:
1848:
1846:
1831:
1830:
1826:
1821:
1819:
1818:
1809:
1807:
1806:
1797:
1795:
1787:
1786:
1783:
1777:
1774:
1772:
1769:
1767:
1764:
1762:
1759:
1757:
1754:
1752:
1749:
1747:
1744:
1742:
1739:
1737:
1734:
1733:
1731:
1729:Miscellaneous
1727:
1721:
1718:
1716:
1713:
1711:
1708:
1706:
1703:
1701:
1698:
1696:
1693:
1691:
1688:
1686:
1683:
1681:
1678:
1676:
1673:
1671:
1668:
1665:
1662:
1660:
1657:
1655:
1652:
1650:
1647:
1645:
1642:
1640:
1637:
1635:
1634:Heat detector
1632:
1630:
1627:
1625:
1622:
1620:
1617:
1615:
1614:Door security
1612:
1610:
1607:
1605:
1602:
1600:
1597:
1595:
1592:
1590:
1587:
1586:
1584:
1582:
1578:
1572:
1569:
1567:
1564:
1562:
1559:
1557:
1554:
1553:
1551:
1549:
1545:
1539:
1536:
1534:
1531:
1529:
1526:
1524:
1521:
1519:
1516:
1514:
1511:
1509:
1506:
1504:
1501:
1499:
1496:
1494:
1491:
1489:
1486:
1484:
1481:
1479:
1476:
1474:
1471:
1469:
1466:
1464:
1461:
1459:
1456:
1455:
1453:
1449:
1443:
1440:
1438:
1435:
1433:
1430:
1428:
1425:
1424:
1422:
1418:
1412:
1409:
1407:
1404:
1402:
1399:
1397:
1394:
1392:
1389:
1387:
1384:
1382:
1379:
1377:
1374:
1372:
1369:
1367:
1364:
1362:
1359:
1357:
1354:
1353:
1351:
1347:
1341:
1338:
1336:
1333:
1331:
1328:
1326:
1323:
1321:
1318:
1317:
1315:
1311:
1305:
1302:
1300:
1297:
1293:
1290:
1288:
1285:
1283:
1280:
1279:
1278:
1275:
1273:
1270:
1268:
1265:
1263:
1260:
1258:
1255:
1253:
1250:
1248:
1245:
1244:
1242:
1238:
1233:
1223:
1220:
1218:
1215:
1213:
1210:
1208:
1207:Master keying
1205:
1203:
1202:Key relevance
1200:
1198:
1195:
1193:
1190:
1188:
1185:
1183:
1180:
1179:
1177:
1173:
1169:
1165:
1161:
1157:
1150:
1145:
1143:
1138:
1136:
1131:
1130:
1127:
1115:
1114:
1105:
1103:
1102:
1093:
1092:
1089:
1083:
1082:Template:HVAC
1080:
1078:
1075:
1073:
1072:Template:Fire
1070:
1069:
1067:
1063:
1057:
1054:
1052:
1049:
1048:
1046:
1042:
1036:
1033:
1031:
1028:
1026:
1023:
1021:
1018:
1015:
1012:
1010:
1007:
1005:
1002:
1000:
997:
995:
992:
990:
987:
985:
982:
980:
977:
976:
974:
970:
963:
960:
957:
954:
951:
948:
945:
942:
939:
936:
933:
930:
929:
927:
923:
917:
914:
912:
909:
907:
904:
902:
899:
896:
893:
891:
888:
886:
883:
881:
878:
876:
873:
871:
870:Duct cleaning
868:
867:
865:
859:
853:
850:
848:
845:
843:
842:Heat detector
840:
838:
835:
833:
830:
828:
825:
823:
820:
818:
815:
813:
810:
808:
805:
803:
800:
798:
795:
794:
792:
790:
786:
780:
777:
775:
772:
770:
767:
765:
762:
760:
759:Smoke control
757:
755:
752:
750:
747:
745:
742:
740:
737:
735:
732:
730:
727:
725:
722:
720:
717:
715:
712:
710:
707:
705:
702:
700:
697:
695:
692:
690:
687:
685:
682:
680:
677:
675:
672:
670:
667:
665:
662:
660:
657:
655:
652:
650:
647:
645:
642:
640:
637:
635:
632:
630:
627:
625:
622:
620:
617:
615:
612:
610:
607:
605:
602:
601:
599:
595:
589:
586:
584:
581:
579:
576:
574:
571:
568:
565:
563:
560:
558:
555:
553:
550:
548:
545:
543:
540:
538:
535:
533:
530:
528:
525:
523:
520:
518:
515:
513:
510:
508:
505:
503:
500:
498:
495:
493:
490:
488:
485:
483:
480:
478:
475:
473:
470:
468:
465:
463:
460:
458:
455:
453:
450:
448:
445:
443:
440:
439:
437:
433:
428:
418:
415:
413:
410:
408:
405:
403:
400:
398:
395:
393:
390:
388:
385:
383:
380:
378:
377:Heat transfer
375:
373:
370:
368:
367:Friction loss
365:
363:
360:
358:
355:
353:
350:
348:
345:
343:
340:
338:
337:Fire triangle
335:
333:
330:
328:
325:
323:
320:
318:
315:
313:
310:
308:
305:
303:
300:
298:
295:
293:
290:
287:
284:
282:
281:Conflagration
279:
277:
274:
272:
269:
266:
263:
261:
258:
257:
255:
251:
247:
240:
235:
233:
228:
226:
221:
220:
217:
211:
208:
207:
188:
184:
178:
176:
160:
156:
150:
146:
136:
133:
131:
128:
127:
121:
119:
114:
112:
102:
98:
96:
92:
87:
85:
80:
76:
71:
69:
68:electromagnet
59:
57:
53:
49:
45:
41:
40:mag hold open
37:
33:
29:
19:
1822:
1810:
1798:
1740:
1680:Piezo switch
1589:Alarm device
1556:Lock bumping
1548:Lock picking
1508:Luggage lock
1458:Bicycle lock
1442:Keycard lock
1335:Skeleton key
1287:Mortise lock
1267:Key retainer
1164:lock picking
1160:locksmithing
1112:
1100:
999:Flame spread
885:Fireproofing
863:and services
764:Smoke damper
754:Safety glass
689:Fire hydrant
654:Fire curtain
628:
614:Booster pump
573:Relief valve
537:Fusible link
327:Fire loading
322:Fire control
292:Deflagration
190:. Retrieved
186:
163:. Retrieved
158:
149:
115:
108:
99:
95:door closers
88:
72:
65:
43:
39:
35:
31:
27:
25:
1776:Puzzle lock
1761:Lock Museum
1695:Reed switch
1604:Card reader
1513:Night latch
1463:Bramah lock
1356:Warded lock
1192:Key control
719:Grease duct
674:Fire escape
664:Fire damper
557:Intumescent
502:Fire safety
467:Fire bucket
362:Flash point
105:Reliability
1845:Categories
1639:Key switch
1488:Door chain
1320:Berlin key
1016:(NFPA 101)
979:CE marking
832:Fire drill
435:Technology
332:Fire point
317:Fire class
297:Detonation
192:2023-03-14
165:2023-03-14
141:References
75:ball joint
1856:Fasteners
1619:Dual loop
1599:Car alarm
1561:Locksport
1483:Dead bolt
1478:Crash bar
1401:Time lock
1340:Smart key
1257:Key blank
972:Standards
901:Fire test
729:Occupancy
694:Fire pump
684:Fire hose
669:Fire door
649:Exit sign
624:Crash bar
397:Pyrolysis
392:Pool fire
357:Flashover
312:Explosive
260:Backdraft
111:fail-safe
62:Operation
52:fire door
1700:Tripwire
1571:Snap gun
1566:Slim Jim
1538:The Club
1498:Knox Box
1330:Keychain
1292:Rim lock
1262:Key code
1222:Rekeying
1212:Password
1101:Category
1065:See also
994:EN 16034
704:Firestop
659:Fire cut
382:Jet fire
372:Gas leak
288:(HAZMAT)
271:Boilover
124:See also
1381:Padlock
1325:Car key
1277:Lockset
1272:Lockrod
1247:Bitting
1113:Commons
946:(NCEES)
267:(BLEVE)
1644:Keypad
1166:, and
1044:Awards
958:(SFPE)
952:(NFPA)
934:(FEMA)
897:(FSES)
79:swivel
1817:Locks
1666:(PIR)
1503:Latch
1156:Locks
1035:UL 94
989:EN 54
940:(IFE)
569:(PPE)
1829:Book
1805:Keys
1313:Keys
984:EN 3
964:(UL)
77:or
42:or
34:or
26:An
1847::
1162:,
1158:,
185:.
174:^
157:.
1148:e
1141:t
1134:v
238:e
231:t
224:v
195:.
168:.
30:(
20:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.