Model-TR-7-UL

Supported Applications

The Dwyer Series TR-7 SAFE-T-GROUND is a ground and continuity control system designed for truck grounding applications. The device ensures safe grounding during loading operations to prevent static discharge hazards. It operates by monitoring the connection between a contactor handle and grounding studs on a vehicle, utilizing an internal relay system with optional pilot lights to indicate grounded or ungrounded status.

Operating Conditions & Performance

The TR-7 unit requires rigid mounting near the truck grounding location under a protective canopy. The enclosure is not waterproof and must be kept dry during operation. Power supply requirements are 105–125 VAC, connected via terminals designated for input (Terminals 7 and 8) with a green earth ground wire connection at Terminal G.

The system provides relay outputs through two sets of contacts:

• Relay #1: Terminals 1 (N.O.), 2 (Common), 3 (N.C.)
• Relay #2: Terminals 4 (N.O.), 5 (Common), 6 (N.C.)

The unit does not ground the loading structure or equipment; it monitors continuity between the truck and a grounding point.

Mechanical Specifications

• Overall Dimensions: Height 8 [203.20], Width 6-5/8 [168.28], Depth 5-5/8 [142.88]
• Electrical Connection: 3/4 FEMALE NPT CONDUIT CONNECTION
• Cord Connector Type: Mil-Spec cord connector (Part #4G)

Configuration Options

The series supports various configurations through a range of accessories and replacement parts. The system is designed to be used with specific contactor handles connected to grounding studs on the truck.

• Contactors: Stud type (#4, #4A) or Battery type (#4B, #4C). Note: The 'Battery Clamp' type Contactor (P/N 84-200615-00) is for temporary use only and should be replaced with a 'Stud Type' Contactor when grounding studs are fitted.
• Cords: Coiled cord options include standard length (#4F, 15 ft) or extended length (#4F-X, 30 ft).
• Grounding Studs: Brass grounding studs (#4H, two required per truck) and Temporary grounding stud assembly (#4H-T).
• Circuit Replacement: ICC-7 (TR-7 internal chassis circuit complete assembly).

The series includes multiple SKUs representing different configurations of the base unit, including models TR-7, TR-7-B, TR-7-L, and variations with suffixes such as -U, -X, and combinations thereof.

Key Product Differences

Variants in the Model-TR-7-UL series differ by specific accessory inclusion or configuration options denoted by model suffixes. The base unit (TR-7) serves as the core ground monitoring system, while other variants may include integrated pilot lights or different relay configurations.

• Model Suffixes: Variants such as TR-7-B, TR-7-L, and combinations like TR-7-XBL indicate specific feature sets available within the series envelope.

The system requires that components not be substituted or adjusted; specifically, the slider resistor must not be adjusted. The 'Battery Clamp' type contactor can be clamped to an unauthorized ground if used improperly, which defeats the purpose of the TR-7 SAFE-T-GROUND system.