Making Connections

April 2, 2015
Molex Low Voltage Wire Connectors simplify electronic access control installations

When installing a component based, hard-wired, electromechanical access control system, wiring is required. These low voltage components must be interconnected. There is wiring from the power source and wiring from the network or controller. There is wiring from the lock, the credential reader, exit bar and any other components including key switch, push button, sensors, switches, accessories, fire panel, etc.  Then, there can be the wiring from and to a pre-wired power transfer such as an electrified hinge.

All of these components have specific current requirements, and depending upon the length of the long wire runs must be considered as they can affect the wire gauge. Once wire gauge and lengths are determined, the next step is to install the components and make the wiring connections. There are many different methods to interconnect component-based electromechanical access control systems.

The controllers, interface panels, power supplies and other circuit board components usually have screw or screwless terminals. Electrified locking hardware, credential readers, key switches and power accessories are usually equipped with wire leads. Depending upon the manufacturer and the application, locking hardware including electromagnetic locks can have either.

For components that have wire leads or require a secondary connection, there are a number of methods to connect wires. Low voltage wires can use a permanent (non-reusable) method of connection such as solder, flux and black electrical tape or shrink tubing for insulation and to prevent moisture damage. Soldering wires is time-consuming and depends upon the installer’s expertise. If changes need to be made, the conductors can be cut, stripped, soldered and sealed.

One step forward is the crimp connectors that require removal of a portion of the wire's insulation. Crimp connectors have a metallic sleeve with an insulated housing in which the stripped wires are inserted. A crimping tool compresses the sleeve against the wires. The quality of the compression varies dramatically by the tool and the operator's expertise. Squeezing too hard can damage the sleeve, resulting in the damage to the wiring and then sliding out of the sleeve. Not squeezing hard enough can result in the wiring sliding out of the sleeve.

Part of the problem is the number of strands in the wire. For example, according to Molex, "there can be more than 18% more material in an 18 AWG by 19-strand wire than an 18 AWG by 16-strand wire. Insulation on an 18 AWG wire can range from 1.78mm (.070") to over 4.57mm (.180"). Wire strands can be copper, tinned, over coated, or top coated. Wire insulation materials, thickness, and durometers vary from application to application."

To help holding power as well as maintain current integrity, some crimp connector manufacturers have added sealant to their butt connectors. The sealant is released when crimped.

Crimp connectors have been redesigned to include a second crimping. This second crimp requires an additional crimp section in the metal sleeve. One part crimps on the wire and the second crimps on its insulator. The second crimp provides strain relief because this crimp is designed to work against stress exerted on the conductor.

Newer technology includes Insulation Displacement Technology (IDT), which does not require removal of the insulation for termination. An Insulation Displacement Connector (IDC) forces the insulated wire into a terminal slot that is smaller than the wire diameter. This operation "displaces" the insulation, making electrical contact all in one step. There is no separate step for stripping the wire.

There are two problems with IDCs. First, the "V" that cuts through the insulation can also cut through the wire strands, decreasing the current handling ability. Second, the termination depends upon the wire staying within slot.

The IDC is a permanent type of connector that must be either disassembled or cut off in order to disconnect.

Some IDCs are designed to accommodate two or more solid wires that are press fit. These connectors reduce the outer diameter, which keeps the wires within the butt style connector. 

To reduce the time required for manufacturing, a different technology was developed to connect two wires which can be plugged together and unplugged multiple times.

The most common is the Molex or Amp connector style two-piece pin and socket interconnection that can be disconnected. The basic concept is two-part design using a pin and a socket style terminal. The pin terminal slides into the socket terminal and is press fit in place. The pin terminal can be removed from the socket without damage. The pin and the socket are held in two-piece gendered nylon plugs and receptacles, which accommodate from two to more than 50 pin and socket interconnections.

For the purpose of this article, I had access to a Molex Crimping Tool and Kit containing:

  • Molex 43030-0007 Terminal (female) for 20-24 gauge wire
  • Molex 43031-0007 Terminal (male) for 20-24 gauge wire
  • Molex 43030-0010 Terminal (female) for 26-28 gauge wire
  • Molex 43031-0010 Terminal (male) for 26-28 gauge wire
  • Molex 43025-0200 2 position Receptacle (use female terminals)
  • Molex 43020-0201 2 position Plug (use male terminals)
  • Molex 43025-0400 4 position Receptacle (use female terminals)
  • Molex 43020-0401 4 position Plug (use male terminals)
  • Molex 43025-0800 8 position Receptacle (use female terminals)
  • Molex 43020-0801 8 position Plug (use male terminals)
  • Molex 11-03-0043 Terminal Extraction Tool

The Molex Tool used in this article is the Type 4D, a full cycle ratcheting hand tool that ensures complete crimps. Its user-friendly terminal locator wire stop holds terminals in the proper crimping position.

The pin and socket terminals each have two crimp sections, one for the conductor and one for the insulation.

The process of assembling this style of connector is to strip a small amount of the insulation. Then insert the pin or socket terminal into the Molex crimping tool. Slide the conductor into the terminal. Squeeze the handles together to compress the terminal. Keep pressing the handles together until they release upon completion of the crimp.

The number of pin and socket terminals determines the number of positions in the plug and receptacle. The provided kit has two, four and eight position plugs and receptacles. Insert the male terminals into the plugs and the female terminals into the receptacle.

In case of a problem, the terminals can be removed from the plug or receptacle. When finished, the plug slides into the receptacle.

Securing wires using this type of quick system has been embraced by Allegion, ASSA ABLOY and Stanley Security Solutions.

The Stanley Quick Connect System consists of Best and Precision electrified door hardware and wiring harnesses. Quick Connect System wiring harnesses are shipped with Quick Connect at one end and exposed pin heads or stripped leads at the other.

ASSA Abloy Group companies offer ElectroLynx as a quick-connect method for the electrification of hard-wired component based access control systems. ElectroLynx connectors are on electrified lock hardware from Ceco Door, Curries, HES, McKinney, Pemko, Sargent and Securitron.

Allegion Connect is the factory-installed Molex connector system installed into Von Duprin, Schlage, Falcon and Ives electrified products. Allegion Connect utilizes Molex pin and socket terminals and connectors for quick-connect wiring harnesses and electrified hinges.

For more information, contact:

TE Connectivity Web Site: www.te.com

Molex Web Site: www.molex.com