A-B 700-HT3 Series A Time Delay Relay

Allen-Bradley 700-HT3 Series A Time Delay Relay (Multi-Function Plug-in Timer Module)

Product Description

The Allen-Bradley 700-HT3 is a plug-in, multi-function time delay relay module used in industrial control circuits to provide adjustable timing control for switching operations. It is designed for use with 700-H socket bases and works as a versatile timing accessory for general purpose relays and control systems.

Specifications

• Brand: Allen-Bradley (Rockwell Automation)
• Series: 700-HT
• Model: 700-HT3 (Series A)
• Type: Multi-function time delay relay module
• Supply Voltage: 12–240V AC / DC
• Timing Range: approx. 0.05 s to 100 hours (multi-range selectable)
• Mounting: Plug-in tube base / socket mounted
• Function Modes: Multiple selectable timing functions

Main Timing Functions

The 700-HT3 supports several programmable timing modes, including:

• ON-delay (delay on energization)
• OFF-delay (delay on de-energization)
• Interval / one-shot timing
• Repeat cycle timing
• Signal-controlled delay functions

What it actually does

This device is used to:

• Delay start or stop of electrical loads
• Control motor start sequences
• Prevent short cycling of machines
• Coordinate multi-step automation sequences
• Provide timing logic in relay-based control systems

System Role (Simple)

Control signal → 700-HT3 timer module → relay output → load (motor / valve / contactor)

It acts as a “time-based logic controller in relay systems”.

Key Features

• Multi-function selectable timing modes
• Wide voltage input (AC/DC universal)
• Plug-in modular design for easy replacement
• Adjustable time range (seconds to hours)
• LED status indication (timing state)
• Compatible with 700-H relay sockets
• Industrial-grade reliability

Typical Applications

• Motor control sequencing
• HVAC control systems
• Pump delay control
• Compressor anti-short-cycle protection
• Conveyor automation systems
• Industrial machine timing logic

Advantages

• Flexible multi-mode timing control
• Easy plug-in replacement design
• Wide voltage compatibility (12–240V AC/DC)
• High reliability for industrial environments
• Reduces need for PLC in simple timing logic systems

Important Notes

• Not PLC CPU ❌
• Not I/O module ❌
• Not power supply ❌
• It is a time delay relay / timing control module ✔

Precautions

• Must match correct 700-H socket base
• Incorrect wiring may cause timing malfunction
• Timing accuracy depends on configuration and load conditions
• Not suitable for high-speed precision timing applications