Equipment - Resistance Welding SCR Contactors

Water Cooled SCR's

Direct Water Cooled SCR

Undoubtedly the most popular resistance welding contactor for the past twenty years are SCI's direct water cooled SCR Contactors. The selections shown are in stock in welding current ratings to 3996 Amps RMS at 50% duty cycle. Choose between single or double sided cooled, and in SCR voltages to 2600 Volts. These are the workhorse in medium to heavy KVA welding controllers. Mounting bases and bus bar connections are identical throughout the series therefore offering flexibility and conformity from 15 KVA through 600 KVA designs.

 
Darrah Part Number Welding Rating Amps RMS at 50% duty cycle Welding Rating Amps RMS at 100% duty cycle SCR voltage rating
(PIV) (VRRM)
Water Cooled
SGL DBL
D09ST15
D09ST18
900
900
400
400
1500
1800
X
X
-
-
D13DT15
D13DT18
1300
1300
695
695
1500
1800
-
-
X
X
D13SE18
D13SE20
1300
1300
695
695
1800
2000
X
X
-
-
D18DE18
D18DE20
1800
1800
970
970
1800
2000
-
-
X
X
D21DM18
D21DM20
D21DM26
2100
2100
2100
1225
1225
1225
1800
2000
2600
-
-
-
X
X
X
D26DN18
D26DN20
2600
2600
1710
1710
1800
2000
-
-
X
X
D32DN18
D32DN20
D32DN26
3200
3200
3200
2075
2075
2075
1800
2000
2100
-
-
-
X
X
X
D40DD18
D40DD26
3996
2230
2188
1946
1800
2600
-
-
X
X


Water Requirements: Amps RMS is achieved with a cooling flow rate of 1.2 gallons (4.5 liters) per minute at 40°C water temperature.

Water Connections: Fits 3/8 inch hoses

Thermostat: If required add suffix J to part number

MOV: For MOV add suffix M to part number

Example: 13DT15JM, 1300 Amps RMS, 1500 Volt, with thermostat and MOV.

Click to enlarge diagrams



D09ST & D13SE SERIES
SINGLE SIDED DIRECT WATER COOLED
D21DM & D26DN SERIES
DOUBLE SIDED DIRECT WATER COOLED


D13DT & D18DE SERIES
DOUBLE SIDED DIRECT WATER COOLED


D32DN20J SERIES
DOUBLE SIDED DIRECT WATER COOLED

HS-6 Design

SCI HS-6 design direct double sided cooled SCR Contactors have proven to be dependable for years in resistance welding controllers.
Choose between two popular current ratings with SCR voltages to 1800 Volts.
SCI's HS-6 design switches are available with either 3/8 " or 1/2" water hose connections. As always, thermostats, MOV's and R/C snubbers are easily added.

SCI Part Number Welding Rating Amps RMS at 50% Duty Cycle Welding Rating
Amps RMS at 100% Duty Cycle
SGL. Cycle Surge Current (ITSM) SCR Voltage Rating (PIV) (VRRM)
DO8HS6-16 1200 800 5500 1600
D12HS6-18 1800 1200 7500 1800

DO8HS6 & D12HS6 TYPES
DOUBLE SIDED
DIRECT WATER COOLED

Automotive Style SCR Contactors

SCI Automotive Style SCR Contactors are the chosen favorite among high current/high voltage resistance welding users. All contactors are rated at 100% continuous and are provided with 2600 Volt SCR's.

This series is also popular for frequency converters, seam, and flash butt welding duty cycles.

Bus tang connections are standardized to fit all applications.

Four holes plus center slot. Holes are on 1.06" centers. The center slot is .5" x .75"

SCI Part Number Welding Rating
Amps RMS at 100% Duty Cycle
SGL. Cycle Surge Current (ITSM) SCR Voltage Rating (PIV) (VRRM)
DPH7825-468 1200 10000 2600
DPH7844-468 1700 10000 2600
DPH7845-468 1750 18000 2600
DPH7824-468 2500 18000 2600

DPH7824 SERIES
DIRECT WATER COOLED
AUTOMOTIVE STYLE

5000 Amp Heavy Duty Contactor

SCI's Heavy Duty Contactor ranks as the largest found in the resistance welding industry. Capable of welding current ratings of 8972 Amps at 10% duty cycle, the DPH7847-470 delivers 5144 Amps continuously. This contactor is in our inventory with 2200 Volt rated SCR's. This is truly the choice for heavy seam and flash butt welder controls.

Indirect Water Cooled

SCI offers the resistance welding industry our line of indirect water cooled Contactors. Indirect water cooling refers to SCR Contactors that isolate the welding voltage from the water cooling.

These switches are manufactured in such a way that once installed in a controller, if servicing is required, the contactor is disassembled with a simple allen wrench. The SCR puck assembly can be removed, leaving the water cooled chill block intact, thus eliminating any need to disconnect or reconnect any water lines. The puck assemblies can be replaced or repaired within minutes of a failure with simple tools. Since the puck assemblies are pre-assembled, there is no need to be concerned about special torquing or mounting techniques.

SCI currently offers three types of indirect water cooled SCR Contactors. All three types have the same water cooled chill block, but offer different bus tang or power connections.

Another advantage of our line of indirect water cooled SCR Contactors is that the chill blocks are isolated from the AC line power. Contactors can be mounted directly to the side of the control cabinet, therefore eliminating the need for lengthy hoses in your enclosures.

SCI Part Number Welding Rating Amps RMS at 50% duty cycle Welding Rating Amps RMS at 100% duty cycle SGL. Cycle surge current (ITSM) SCR Voltage rating (PIV) (VRRM) Bus Tang Type
DEC12ISM18-J
1100 600 10000 1800 STRAIGHT
DEC14ISM-18J
1100 600 10000 1800 1 Straight, 1 90° bend
DEC17ISM-18J 1100 600 10000 1800 both 90° bend



DEC14ISM - 18J
INDIRECT WATER COOLED

DEC17SM SERIES SINGLE SIDED
INDIRECT WATER COOLED

Tri Pack Assemblies for Three Phase or Cascade Controls

For Three Phase controls, dual or three cascade controls, SCI offers its line of indirect water cooled contactors mounted on a triple chill block. Choose from either of the three bus tang connections and have us mount them on our specially designed triple heat sink. This means one pair of water connections cools three contactors.

SCI's Tri-pack design is compact, thus eliminating bulky cabinets and excessive water connections.

For lighter KVA systems, we provide Isolated Tri-Pack Module Assemblies. A single water connection provides cooling for three SCR Contactors in a small convenient package.

Choose between 500 Amp or 1000 Amp RMS rated SCR Modules.

Bus bars, thermostat and MOV's are included.

Isolated SCR Modules - Integral Water Cooled

This product line features industry standard dual SCR modules with integral water cooled bases. Our improved design has eliminated thermal barriers associated with separate cooling bases. This has increased current ratings by as much as 15%. In addition, because the water connections are directly tapped to the module base, water leaks are virtually eliminated. To further enhance water integrity, each unit is 100% pressure tested at 150 psi for one minute.

Another significant feature is that the modules are vacuum filled with a high performance, flame retardant silicone -based material at final assembly which eliminates hidden voids inside the package and prevents dust and dirt from penetrating which may cause premature failure.

SCI's integral water cooled modules are available in three popular packages.

SCI Part Number Welding Rating
Amps RMS at 10% Duty Cycle
Welding Rating
Amps RMS at 50% Duty Cycle
Welding Rating
Amps RMS at 100% Duty Cycle
SCR Voltage Rating (PIV) (VRRM) Water Connection Location Package Design
Q20001 1592 1278 717 1800V Side
1-1/2' Centers
MP03
Q20002 1592 1278 717 1800V Bottom
1-1/2' Centers
MP03
Q20003 1592 1278 717 1800V Side 2" Centers MP03
Q20006 1592 1278 717 1800V Side
1-1/2' Centers
MP03
Q20008 1068 755 450 1800V Side 2" Centers MP02
Q20009 1068 755 450 1800V Bottom
2' Centers
MP02
Q20011 2797 1522 1097 1800V Side
1-1/2' Centers
MP04
Q20012 2797 1522 1097 1800V Bottom
1-1/2' Centers
MP04
Q20013 2797 1522 1097 1800V Side 2" Centers MP04

Water requirements: Amps RMS is achieved with a cooling flow rate of 1.2 gallons (4.5 liter) per minute at 40° water temperature

Water connections: 1/4-18 NPT tapped holes

Thermostat: All modules are supplied with an accelerated thermostat sensor, 50°C open on rise and isolated to base 2000 Volts. Thermostat leads are 24 inches long.

Options include: R/C Snubber, MOV's and bus bars.


MP02 Package Design
Q20008 Shown

MP03 Package Design
Shown Q20002

MP04 Package Design
Shown Q20011

Spotwelding Consultants Inc.

4209 Industrial
Rowlett, Texas 75088
Toll Free: 888-255-6780
Phone: 972-475-0874
Fax: 972-475-5024