In order to provide the best user experience, we had to abandon support for Internet Explorer versions prior to IE9. Upgrade your browser.
By: David Howard | G+

About Electrical Contacts

Let’s begin with the basics about contacts. It’s also called a tip, point, finger, wedge, button and segment. A single or multi-pole product that contains movable and stationary contacts, often including screws, springs and possibly other hardware is called a kit or set.

A contact opens and closes (makes and breaks) to engage or interrupt an electrical circuit. It’s made to be replaced. It wears electrically (burning) and mechanically. It is found in switches, relays, contactors and motor starters.

When electricity is supplied to the coil in the contactor, it acts like a magnet. This magnetic action pushes or pulls a magnetic plate that slides or claps the movable contact together with the stationary. Please see the illustration below.

Electrical Contact Example 

Copper only is often the material of choice when making/breaking more than one time per hour. You will often find copper-only contacts in DC applications, particularly cranes. They don’t appear to be copper, because in the great majority of cases, they have been plated. The plating can be with silver, nickel or cadmium. The plating helps prevent the build up of copper oxide (green rust), which is non-conductive.

When closed for long periods of time (8 hours) copper only contacts have a tendency to ’stick’ or weld and need silver pads of varying thickness. Generally speaking, the more amps, the thicker the pad will be. Pure silver pads are found sometimes in DC applications. The material of choice, however, is most often silver-cadmium oxide. The mix is usually 85/15 or 90/10. These contacts are found in most AC contactors for NEMA size 00-6. A 50/50 silver tungsten mix is used for high-amp applications. The tungsten is very hard and often used for circuit breaker applications.

Below you’ll find photos of the basic parts of a contactor. This particular example is a GE size 2, CR305D0** in the 100, 200, 300 Line. The replacement contact set is found on page 53 in the Repco Electrical Contact catalog. The photos are from the top down, as you would take the contactor apart. The sizes of the contactor and various parts are not in relational proportion to each other.

GE Contactor CR305D0**
GE Contactor CR305DO

Top Magnet Assembly
Top Magnet Assembly
 
Operating Coil
Operating Coil

Lower Magnet Assembly
Lower Magnet Assembly
 
Top View - Movable Contact Support
Movable Contact support




Bottom View - Movable Contacts in Support
Movable Contacts In Support

Stationary Contacts in Support
Stationary Contacts In Support

Repco Replacement 3 Pole, Size 2 Contact Set - 9723CG
Repco Replacement 3 Pole Size 2 Contact Set - 9723CG

100
555

4/22/2024 10:33:20 PM

~ ubaTaeCJ

99
555

4/22/2024 10:32:26 PM

~ ubaTaeCJ

98
555

4/22/2024 10:31:36 PM

~ ubaTaeCJ

97
555

4/22/2024 10:31:32 PM

~ ubaTaeCJ

96
555

4/22/2024 10:31:27 PM

~ ubaTaeCJ

95
555

4/22/2024 10:31:26 PM

~ ubaTaeCJ

94
-1´ OR 3*2<Ɛ+5+396-396)

4/22/2024 10:10:40 PM

~ ubaTaeCJ

93
-1´ OR 2+396-396-1=0+0+0+1

4/22/2024 10:10:36 PM

~ ubaTaeCJ

92
555

4/22/2024 9:54:36 PM

~ ubaTaeCJ

91
555

4/22/2024 9:54:09 PM

~ ubaTaeCJ

90
555

4/22/2024 9:53:42 PM

~ ubaTaeCJ

89
555

4/22/2024 9:53:16 PM

~ ubaTaeCJ

88
555

4/22/2024 9:51:57 PM

~ ubaTaeCJ

87
555

4/22/2024 9:51:32 PM

~ ubaTaeCJ

86
555

4/22/2024 9:50:33 PM

~ ubaTaeCJ

85
555

4/22/2024 9:50:32 PM

~ ubaTaeCJ

84
555

4/22/2024 9:50:30 PM

~ ubaTaeCJ

83
555

4/22/2024 9:50:29 PM

~ ubaTaeCJ

82
555

4/22/2024 9:50:03 PM

~ ubaTaeCJ

81
555

4/22/2024 9:49:37 PM

~ ubaTaeCJ

80
555

4/22/2024 9:49:10 PM

~ ubaTaeCJ

79
555

4/22/2024 9:34:10 PM

~ ubaTaeCJ

78
555

2/18/2023 6:21:26 AM

~ jJQaBOcg

77
555

2/18/2023 6:21:12 AM

~ jJQaBOcg

76
555

2/18/2023 6:21:00 AM

~ ElLOV

75
555

2/18/2023 6:20:58 AM

~ 1

74
555

2/18/2023 6:20:57 AM

~ 1’

73
555

2/18/2023 6:20:55 AM

~ jJQaBOcg’| | DBMS_PIPE.RECEIVE_MESSAGE( CHR( 98) | | CHR( 98) | | CHR( 98) ,15) | | ’

72
555

2/18/2023 6:20:44 AM

~ 3HDsGcQo’) ) OR 541=( SELECT 541 FROM PG_SLEEP( 15) )

71
555

2/18/2023 6:20:30 AM

~ d0GONVuZ’) OR 856=( SELECT 856 FROM PG_SLEEP( 15) )

70
555

2/18/2023 6:20:16 AM

~ AsSZeSOf’ OR 384=( SELECT 384 FROM PG_SLEEP( 15) )

69
555

2/18/2023 6:19:15 AM

~ ( select( 0) from( select( sleep( 15) ) ) v) /*’+( select( 0) from( select( sleep( 15) ) ) v) +’+( select( 0) from( select( sleep( 15) ) ) v) +*/

68
555

2/18/2023 6:19:03 AM

~ 0XOR( if( now( ) =sysdate( ) ,sleep( 15) ,0) ) XORZ

67
555

2/18/2023 6:18:52 AM

~ 0’XOR( if( now( ) =sysdate( ) ,sleep( 15) ,0) ) XOR’Z

66
555

2/18/2023 6:18:41 AM

~ if( now( ) =sysdate( ) ,sleep( 15) ,0)

65
555

2/18/2023 6:18:26 AM

~ -1 OR 2+909-909-1=0+0+0+1

64
555

2/18/2023 6:18:25 AM

~ -1’ OR 2+926-926-1=0+0+0+1 or ’HXjJtupU’=’

63
555

2/18/2023 6:18:24 AM

~ -1’ OR 2+984-984-1=0+0+0+1

62
555

2/18/2023 6:18:22 AM

~ -1 OR 2+394-394-1=0+0+0+1

61
555

2/18/2023 6:18:21 AM

~ -1 OR 2+878-878-1=0+0+0+1

60
555

2/18/2023 6:18:21 AM

~ nji4Sv5s

59
555

2/18/2023 6:18:08 AM

~ jJQaBOcg

58
555

2/18/2023 6:17:56 AM

~ jJQaBOcg

57
555

2/18/2023 6:17:43 AM

~ jJQaBOcg

56
555

2/18/2023 6:17:42 AM

~ jJQaBOcg

55
555

2/18/2023 6:17:41 AM

~ jJQaBOcg

54
555

2/18/2023 6:17:25 AM

~ jJQaBOcg

53
555

2/18/2023 6:17:08 AM

~ jJQaBOcg

52
555

2/18/2023 6:16:55 AM

~ jJQaBOcg

51
555

2/18/2023 6:15:31 AM

~ jJQaBOcg

50
555

2/18/2023 6:15:17 AM

~ jJQaBOcg

49
555

2/18/2023 6:15:03 AM

~ jJQaBOcg

48
555

2/18/2023 6:14:50 AM

~ jJQaBOcg

47
555

2/18/2023 6:14:49 AM

~ jJQaBOcg

46
555

2/18/2023 6:14:48 AM

~ jJQaBOcg

45
555

2/18/2023 6:14:46 AM

~ jJQaBOcg

44
555

2/18/2023 6:14:46 AM

~ jJQaBOcg

43
555

2/18/2023 6:14:44 AM

~ jJQaBOcg

42
555

2/18/2023 6:14:31 AM

~ jJQaBOcg

41
555

2/18/2023 6:14:20 AM

~ jJQaBOcg

40
ySQpo

2/18/2023 6:14:07 AM

~ jJQaBOcg

39
1

2/18/2023 6:14:06 AM

~ jJQaBOcg

38
1´"

2/18/2023 6:14:05 AM

~ jJQaBOcg

37
555´||DBMS_PIPE.RECEIVE_MESSAGE(CHRဂ)||CHRဂ)||CHRဂ),15)||´

2/18/2023 6:14:03 AM

~ jJQaBOcg

36
555*DBMS_PIPE.RECEIVE_MESSAGE(CHRဃ)||CHRဃ)||CHRဃ),15)

2/18/2023 6:13:50 AM

~ jJQaBOcg

35
06BfY63l´)) OR 342=(SELECT 342 FROM PG_SLEEPྯ))

2/18/2023 6:13:38 AM

~ jJQaBOcg

34
9YMPyIll´) OR 560=(SELECT 560 FROM PG_SLEEPྯ))

2/18/2023 6:13:26 AM

~ jJQaBOcg

33
QYsA0Jtb´ OR 327=(SELECT 327 FROM PG_SLEEPྯ))

2/18/2023 6:13:14 AM

~ jJQaBOcg

32
-1)) OR 344=(SELECT 344 FROM PG_SLEEPྯ))

2/18/2023 6:13:02 AM

~ jJQaBOcg

31
-5) OR 249=(SELECT 249 FROM PG_SLEEPྯ))

2/18/2023 6:12:48 AM

~ jJQaBOcg

30
-5 OR 610=(SELECT 610 FROM PG_SLEEPྯ))

2/18/2023 6:12:36 AM

~ jJQaBOcg

29
(selectƐ)from(select(sleepྯ)))v)/*´+(selectƐ)from(select(sleepྯ)))v)+´"+(selectƐ)from(select(sleepྯ)))v)+"*/

2/18/2023 6:10:58 AM

~ jJQaBOcg

28
0"XOR(if(now()=sysdate(),sleepྯ),0))XOR"Z

2/18/2023 6:10:45 AM

~ jJQaBOcg

27
0´XOR(if(now()=sysdate(),sleepྯ),0))XOR´Z

2/18/2023 6:10:32 AM

~ jJQaBOcg

26
if(now()=sysdate(),sleepྯ),0)

2/18/2023 6:10:16 AM

~ jJQaBOcg

25
-1" OR 2+828-828-1=0+0+0+1

2/18/2023 6:10:04 AM

~ jJQaBOcg

24
-1´ OR 2+664-664-1=0+0+0+1 or ´6YQVTbeY´=´

2/18/2023 6:10:03 AM

~ jJQaBOcg

23
-1´ OR 2+581-581-1=0+0+0+1

2/18/2023 6:10:02 AM

~ jJQaBOcg

22
-1 OR 3*2>Ɛ+5+383-383)

2/18/2023 6:10:01 AM

~ jJQaBOcg

21
-1 OR 3*2<Ɛ+5+383-383)

2/18/2023 6:10:00 AM

~ jJQaBOcg

20
-1 OR 3+383-383-1=0+0+0+1

2/18/2023 6:09:59 AM

~ jJQaBOcg

19
-1 OR 2+221-221-1=0+0+0+1

2/18/2023 6:09:56 AM

~ jJQaBOcg

18
I3VSewKN

2/18/2023 6:09:55 AM

~ jJQaBOcg

17
555

2/18/2023 6:09:40 AM

~ jJQaBOcg

16
555

2/18/2023 6:09:27 AM

~ jJQaBOcg

15
555

2/18/2023 6:04:34 AM

~ jJQaBOcg

14
555

2/18/2023 6:04:21 AM

~ jJQaBOcg

13
555

2/18/2023 6:03:37 AM

~ jJQaBOcg

12
555

2/18/2023 6:03:25 AM

~ jJQaBOcg

11
555

2/18/2023 6:02:11 AM

~ jJQaBOcg

10
555

2/18/2023 6:02:00 AM

~ jJQaBOcg

9
555

2/18/2023 6:01:49 AM

~ jJQaBOcg

8
555

2/18/2023 6:01:38 AM

~ jJQaBOcg

7
555

2/18/2023 6:01:37 AM

~ jJQaBOcg

6
555

2/18/2023 6:01:36 AM

~ jJQaBOcg

5
555

2/18/2023 6:01:20 AM

~ jJQaBOcg

4
555

2/18/2023 6:01:08 AM

~ jJQaBOcg

3
555

2/18/2023 5:46:39 AM

~ jJQaBOcg

2
555

9/6/2022 10:59:39 AM

~ ARzZfuRY

1
Very informative and helpful. Thanks

5/15/2012 1:36:30 PM

~ bill

Leave A Comment Now


International: 856-762-0172
Domestic: 800-822-9190

Repco Quick Contact

If you do not see what you need, please let us know what it is and we''ll do our best to help you.

First name required.
Last name required.
Company required.
Valid email required.
Phone number required.
If you are looking for a quote, please include model & quantity in your comments!
Comment required.
Send your inquiry now and we will respond promptly.
Interest is in general information for About-Electrical-Contacts.
Please check the recaptcha box.

Site Search

OEM, Product, Repco ID #s or Terms