Informações Técnicas

Basic description of clearance and creepage


General information on wire sizes



Application Groups as per UL and CSA specifications are outlined in this document.

VDE ratings are outlined based on degree of pollution, clearances, creepage distances and insulating materials.

CSA Group – Certification Record

UL Online Certifications Directory

Quality Assurance

California Proposition 65


Canadian environment protection act

Cobalt Reporting


Conflict Minerals Policy


Conflict Minerals Reporting

Extended Minerals Reporting


Forced Labor & Human Trafficking


Huawei Final Rule

ISO 9001


Kobe Steel

Montreal Protocal


Persistent organic pollutants (POPs)

PFAS Declaration

RoHS, WEEE, REACH and RPFOS requirements.

TSCA Declaration

WECO is committed to comply with all global environmental regulations :



Yes, by using jumper combs. NOTE:  The jumper nomenclature follows the same 300 series terminal block; example a 324 -HDS/05 will use a jumper 324-J/05

The RAST 5 standard is a coding sequence in Europe used by manufacturers of major appliances and consumer products such as whitegoodsr (fridge, oven, etc.). This specific standard prevents mismatching of the plug and header to avoid short circuits on the PCB. Our 130 product family follows this standard and could be used for these specific applications within Europe.

As per WECO quality control documentation, insertion force and contact resistance after 100 plug/de-plug cycles has been verified and guaranteed.

When WECO speaks of continuous temperature limits, it refers to the material and not the environment. The temperature of a terminal block is a combination of heat generated by the electrical current flowing through it and heat exchanged with its environment. The heat exchange (inwards and outwards) with the environment is a combination of conduction, convection & radiation. The environment is the atmosphere, the enclosure, the wires, the mounting surface, other components and so on. We can see that the temperature of the environment is complex and cannot easily be reduced into the temperature of the surrounding air. We are concerned with hot spots in the connector's components (internal and external) and the material's ability to withstand this safely. Continuous temperatures always refer to the temperature of the connector materials. In the case that an RTI temperature is given, this means that the dielectric polymeric resin material was tested to UL 746B Polymeric Materials Long Term Property Evaluations and its Relative Thermal Index (RTI). This test last 5000 hours and the mechanical & electrical properties must not deteriorate more than 50%. Both UL 1059 Terminal Block Standard & CSA 22.2 no. 158 Terminal Block Standard refer to RTI. UL 1059 & CSA 22.2 no. 158 apply to ambient temperatures of 40 C (104 F) or less, the tests were done at 15 to 35 C (59 to 95 F). Ambient temperatures above 40 C (104 F), in principle and in practice, would require material review, special marking, extra testing and derating.

WECO gives maximum torques for the wire tightening screws but does not give torques for mounting screws. The reason is that mounting screw torque will be very affected by the type of screw used and the substrate in which it is screwed. For example a wood screw into wood, plastic or sheet metal; predrilled or not, a machine screw & nut, will all have different torques. The important thing is not to deform, penetrate or break the connector dielectric moulding material because this could cause short circuits and other failures. As such the correct screw insertion criteria are correct final height of the screw head against the moulding and proper penetration into the mounting surface so as to be solid without damaging anything. The drawings on the website will help in determining this. This also requires that screw heads (and washers if used) be correctly sized. Too large can cause penetration into sidewalls and too small can cause excessive stress on the mounting hole. WECO sometimes recommends a mounting screw type, but never torque.

UL and CSA recognized or listed terminal blocks have rated torques. Traditionally UL expresses torque in pound-force-inch (lbfin) and CSA expresses torque in Newton-meter (Nm). For example 1 Nm = 8.85 lbfin and 1 lbfin = 0.113 Nm.

These torques are chosen from UL and CSA tables or by the manufacturer. All cases involve the screws being tightened to the rated torque and the product being subjected to mechanical and electrical tests. This rated torque must be taken as a rating. It must not be exceeded because this could break or deform the connector. It must not be taken as a minimum because this could crush some small soft wires and provoke circuit malfunctions.

Choosing the correct tightening torque for factory wiring or for field wiring involves the knowledge and application of the ratings, torque measuring instruments, torque limited screw drivers, correct screw driver bits, correctly sized screw drivers, and the human factors involved. Mechanically assisted screw drivers (electrical, pneumatic, hand held or fixed) are especially sensitive to misuse. Torque measuring instruments and torque limited screw drivers must be used properly. Improper use can give false readings and incorrect torques. They all have finite accuracies, precisions and resolutions. The human factors involve the installer's strength, ability and choice of tool. In some jurisdictions electrical technicians must have the experience, education and tools required. Over tightening or under tightening can provoke failures that are not immediately obvious and cause overheating, fire or circuit failure. Screw driver bits must be correctly sized for the screw heads. Screw driver bit types such as Pozidrive, Phillips, Robertson and flat blade all perform differently. Screw heads such as Pozidrive, Phillips, Robertson and slot have differences and similarities of performance depending of what screw bit is used.

The ratings are assigned by regulatory agencies according to standards based on National Electrical Code. The values of the voltage and current rating for WECO Terminal Blocks are for both AC and DC applications.

Tin is a soft metal that adheres well to copper.

Dipping a properly prepared clean stranded copper wire into molten tin will agglomerate all the strands. No strands will be loose to twist out of the wire entry. Loose strands could cause a short circuit or reduce the available current carrying capacity.

Tin has a low contact electrical resistance because it is soft. Tin is so soft that moderate contact forces tend to squeeze it so that the microscopic contact points spread into each other. The effective contact surface area is thus increased.

In the case of the high contact forces occurring in screw tightened connections tinned wires or bare wires would have the same contact resistance.

UL 1059 and CSA 22.2 no. 158 terminal block standards require that bare copper wires be used during testing.

The major difference between a genuine surface mount terminal block and through-hole reflow terminal block is that the surface mount does not require any type of holes in the printed circuit board in order to make the solder assembly.

The major similarity between the two is that both are assembled to the surface of the PCB by using re-flow technology. Re-flow technology requires an oven that heats (by convection or radiation) up to 260 - 270 degrees Celsius to melt the solder paste between the contact element and the PCB pad.

An example of a SMarTconn terminal block of THR type is 970-THR. An example of a SMarTconn terminal block of genuine SMT type is 140-A-126-SMD.

Using genuine SMT products increases the surface utilization of the PCB, since you can use both sides. It is appropriate for pick & place automated assembly and completely eliminates PCB damages that are inherent to THR products. Basically it is the higher reliability and the cost impact at PCB assembly level, that make the genuine SMT product line the option of the future.

The disadvantage of the genuine SMT product line is the weaker retention strength of the contact pins to the PCB pad, and the need to change the PCB layout when making the shift from THR to SMT.

Despite the assembly strength and reliability of THR connectors, during the first decade of the new century, the shift between THR and SMT will become more and more popular.


  1. SCCR ratings have long existed in United States for certain components such as fuse holders.

The SCCR requirement was expanded with the release on the 2005 NEC, where marking of SCCR became required to:

HVAC equipment

Industrial Control panel

Industrial Machinery

Meter Disconnect Switches

Motor Controllers

Subsequently in 2006 this requirement has become a part of:

UL508A for Industrial Control Panels.

UL1059 for Terminal Blocks, supplement SA1, 2, 3, and 4, as optional

  1. WECO Terminal Blocks type 302 (HDS), 323(HDS), 324(HDS), 326(HDS), 327(HDS), 327-FU(HDS) are approved according to requirement of standard UL1059.

WECO Terminal Blocks type 302 (HDS), 323(HDS), 324(HDS), 326(HDS), 327(HDS), 327-FU (HDS) are not evaluated for Short Circuit Current Rating yet.

WECO Terminal Blocks type 302 (HDS), 323(HDS), 324(HDS), 326(HDS), 327(HDS), 327-FU (HDS) don’t have SCCR.

Customer may use WECO products and evaluate the final assembly (control panel, machinery, equipment) for SCCR.

  1. Terminal Blocks type 302 (HDS), 323(HDS), 324(HDS), 326(HDS), 327(HDS), 327-FU(HDS)

are approved by regulatory agencies in North America and Europe

3.1.      UL safety standards UL1059 and UL486E

3.2.      CSA safety standard C22.2 No.158

3.3.      European safety standards

DIN EN 60998-1(VDE 0613-1), DIN EN 60998-2-1(VDE 0613-2-1) EN 60998-2-1

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