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Today's automation and control industry offers many technological advancements, yet many manufacturers and integrators are still using old style panel mount barrier strips to terminate wires. With the perception of being "cost effective," barrier strips have held on to some manufacturers' specifications. While they may be cost effective when comparing one terminal to another, a deeper look reveals quite the opposite. This article compares DIN rail mount terminal blocks to panel mount barrier strips with respect to features, benefits and overall cost.
Electrical Protection
Barrier strips have an open construction that allows contact with the metal parts of the connector. If a system is under load, the chance of being electrically shocked with this open design is high, and a short is possible. The short could stem from cut strands of wire during the installation, a screwdriver being accidentally placed across the barrier strip or two adjacent spade terminals coming in contact.
DIN rail mount terminals blocks have enclosed construction that does not allow contact with the metal parts of the connector. Its plastic housing offers screw turrets into which the screws are recessed. Likewise, the current carrying bar is completely protected by the plastic housing. With the hardware safely insulated, the potential for electrical shock or accidental shorting can be reduced or completely eliminated.
Unlike barrier strips, accessories for DIN rail mount terminals increase the safety of the control cabinet. Jumpers, used to common the potential of two or more circuits, are available with insulation to provide electrical protection. Most barrier strips only offer a tin plated copper jumper comb without insulation, which increases the possibility for electrical shock and accidental shorting. Additionally, partition plates increase the creepage clearance...