Eaton S801+Soft Starter Complete Guide

Terminal 1: Start command (triggered by level or edge, depending on DIP switch S1 setting)

Terminal 2: Jog (Jog)

Terminal 3: Overload protection disabled during startup (for debugging only)

Terminal 4: Reset

Auxiliary contacts: Terminals 13, 14, 95, 96, 98 provide relay outputs that can be used to indicate operating status or faults. Contact capacity: 3 A/120 Vac or 24 Vdc, maximum 10 A (resistive).

3.4 DIP switch settings

The detection method for selecting the start command of S1 switch:

OFF (factory default): Level triggered, that is, when terminal 1 maintains 24 Vdc, as long as the allowable conditions are met and there are no faults, the motor will start.

ON: Edge trigger, which means that terminal 1 must have a rising edge from 0 to 24 Vdc to start, and the rising edge must be reapplied after fault reset.

The S2 switch has no function in S801+.

Working principle and start/stop mode

S801+uses six thyristors internally to form a three-phase fully controlled bridge. During the starting process, by gradually increasing the conduction angle of the thyristor, the motor terminal voltage is smoothly increased from the preset initial torque value to the full voltage. When the motor approaches synchronous speed, the internal bypass contactor closes, the thyristor is short circuited, and the motor is directly powered by the power supply, thereby reducing thyristor losses.

4.1 Voltage ramp starting

This is the most commonly used mode. The voltage starts from the initial torque value and linearly increases to full voltage within the set soft start time. If the motor reaches synchronous speed ahead of schedule, the bypass contactor will close early, and the soft start time may be shortened.

4.2 Current limit starting

In this mode, the soft starter maintains a constant current upper limit (determined by the initial torque setting) instead of a voltage ramp. Suitable for situations where strict limitation of grid surge current is required. Attention: It is not recommended to use it for variable torque loads such as fans and pumps.

4.3 Kick Start

For loads with high static friction, a short-term high torque pulse can be applied during the initial start-up period. The sudden jump torque and duration can be set separately through the potentiometer on CIM.

4.4 Soft Stop

When stopping, the voltage gradually decreases within the set soft stop time, causing the motor to slowly stop to avoid water hammer effect or mechanical shock. Attention: Soft stop is not braking and will not shorten the downtime.

Parameter setting and protection function

5.1 Control Interface Module (CIM)

CIM is installed on the S801+front panel and provides the following configuration components:

FLA potentiometer: Set the motor's full load current (range: 32% to 100% of the frame's rated current).

Starting time potentiometer: 0.5-180 seconds.

Initial torque potentiometer: 1% to 85%.

Jump torque/time potentiometer.

Soft stop time potentiometer: 0-60 seconds.

Overload level DIP switch: optional levels 5-30, default 20.

Fault indicator light: The S.S. Trip LED flashes to indicate a fault code.

5.2 Protection parameters and fault codes

S801+has multiple built-in protection functions that can be enabled/disabled through CIM:

Overload protection (thermal memory model)

Stall: When starting, the motor has not reached synchronous speed and the current is greater than 2 × FLA.

Jam: Current>3 × FLA during operation.

Lack of phase/phase sequence/phase imbalance

SCR short circuit/open circuit detection

Bypass contactor malfunction

Control power undervoltage

When a malfunction occurs, the S.S. Trip LED lights up, and the flashing code can be read by pressing and holding the reset button. For example:

Description of code faults, possible causes, and countermeasures

11. Excessive thermal overload load, low FLA setting, and frequent starting.

14 phase sequence error. The incoming phase sequence does not match the set value. Swap two phases.

The 22 phase loss fuse is blown and the circuit is disconnected.

32 SCR short circuit SCR breakdown, measure phase to phase resistance to confirm.

The control voltage is low, and the 24V power supply capacity is insufficient or the line voltage drop is too large.

5.3 Thermal Overload Model

S801+uses a thermal memory model to simulate motor temperature rise and can provide overload protection levels 5, 10, 20, and 30 as specified in IEC 60947-4-2. The heat accumulation value is stored in non-volatile memory and will not be lost when powered off. After each overload trip, the reset suppression time gradually increases (3 minutes for the first time, 6 minutes for the second time, and 9 minutes for the third time) to allow the motor to cool down.

Typical wiring and application precautions

6.1 Three wire button control

The manual provides wiring diagrams for three wire and two wire button systems. Typical three wire wiring: the stop button (normally closed) is connected in series with the allowable circuit (terminal P), and the start button (normally open) is connected to terminal 1. Auxiliary contacts can be used to indicate operational status.

6.2 Selection of 24 Vdc Power Supply

S801+requires control of power capacity: steady-state 25 W, surge 240 W for 150 ms. It is recommended to use Eaton PSG series power supplies, such as PSG240E (240 W) or PSG480E (480 W).