ABB PSR6-600-70 Compact Soft Starter, 6.8 A

The PSR6-600-70 is the 6.8 A size of ABB’s compact PSR softstarter range, ordered as 1SFA896104R7000. Voltage is ramped up on start and down on stop, which spares couplings, belts and pipework from the shock of a direct-on-line start. Two phases are controlled and an integrated bypass takes over at the top of the ramp, which cuts losses and avoids a separate bypass contactor. It is intended for small pumps, fans and conveyors of about 3 kW at 400 V, within the pump, fan, compressor and conveyor duties ABB describes.

More starters are shown under motor soft starters; for a larger motor see the PSR30-600-70 page.

Technical specifications

Duty limits of the PSR6

The 6.8 A figure is the maximum rated operational current, not a power guarantee, so size the starter from the motor nameplate current. ABB’s starts-per-hour data assume 40 C ambient, a starting current of 4 x Ie and a 6 second ramp; under those conditions the PSR6 handles a 6.8 A motor at 10 starts per hour without a fan and 20 with the auxiliary fan. Above 40 C and up to 60 C the rated current falls by 0.8 percent per degree. For installations higher than 1000 m use the formula percent of Ie = 100 – (x – 1000)/150, where x is the altitude in metres; 4000 m is the maximum. For heavy starts or higher starting rates ask ABB’s softstarter selection tool, or step up a size.

For short-circuit and overload protection the catalogue lists MS116, gG 16 A, J-type 35 A, TF42 and AF9 as one example set. The line contactor is not needed by the softstarter itself, but it is often used to open the circuit if the overload relay trips. Connection kits join the PSR6 to the manual motor starter, and a fieldbus plug adapter (PS-FBPA) can be added. Other short-circuit protection devices can be checked in ABB’s online coordination tool.

Installation of the PSR6

Housing group PSR3 to PSR16 applies, with IP20 main circuit and control circuit and 12 VA at 100-240 V AC; the starter mounts on a DIN rail or with screws. Ramp and voltage limits are set on three dials, and two LEDs report On/Ready and Run. The narrow housing lets several starters share one enclosure. Check ventilation clearances in the manual before stacking units.

Nearby types in the 100-240 V AC range

These types sit next to the PSR6 in ABB’s order list for the 100-240 V AC control versions.

Key features of the PSR compact softstarter

• Integrated bypass: once the motor reaches full voltage the thyristors are bypassed by internal contacts, so the starter dissipates only a few watts in continuous running and no external bypass contactor is needed.
• Soft start and soft stop: the voltage ramp limits starting current and torque; the stop ramp reduces water hammer in pump lines and prevents products from tipping on conveyors.
• Simple set-up: start ramp, stop ramp and initial voltage are adjusted on front dials, without software or a display.
• Same width as a manual motor starter: the PSR6 can be combined with an MS116 or MS132 via a connection kit to form a compact starter unit on the DIN rail.
• Run signal relay: the output can control a line contactor or signal motor status to a PLC.

Soft starter or variable speed drive?

A soft starter like the PSR6 only controls the start and stop; during operation the motor runs at full speed directly from the supply. That makes it the simpler and more compact choice for pumps, fans and compressors that run at constant speed but suffer from mechanical shock, voltage dips or water hammer on direct-on-line starting. If the process needs speed control to save energy or hold a pressure setpoint, a variable speed drive is the better choice. Note also that a soft starter reduces starting current but does not eliminate it, because the motor still needs enough torque to accelerate the load; very high inertia loads may need a larger size or a drive.

Installation and maintenance

• Install vertically and observe the minimum distances between adjacent units given in the installation instructions.
• Coordinate the starter with a short-circuit protection device from ABB’s coordination tables, and provide motor overload protection, for example with a manual motor starter or thermal overload relay.
• Set the start ramp just long enough for a smooth start; an unnecessarily long ramp increases heating in the starter and motor.
• Do not connect power factor correction capacitors between the soft starter and the motor.
• Check terminal tightness and clean dust from the housing during periodic maintenance.

Use in Oman and GCC conditions

The operating range up to 60 °C, with derating above 40 °C, is useful in the region, where motor control panels in pump rooms and plant buildings often run hot. Calculate the derated current for the expected panel temperature in summer and, where needed, select the auxiliary fan or a larger size. Typical local uses include booster pumps in residential and commercial buildings, irrigation and borehole pumps on farms, small ventilation fans and compressors in workshops. On generator-fed sites, soft starting reduces the voltage dip seen by other loads when a motor starts. The IP20 housing requires a dust-protected enclosure in sandy environments.

What to include in your RFQ

• Type PSR6-600-70 and order code 1SFA896104R7000.
• Motor nameplate data, supply voltage and control voltage.
• Number of starts per hour and type of load.
• Required accessories: connection kit, auxiliary fan, fieldbus plug adapter, manual motor starter.
• Quantity and delivery location.

Reading the type code, ordering and documents

PSR is the range, the number is the size, 600 the voltage class, and -70 tells you the control supply is 100-240 V AC; -11 would mean 24 V AC/DC. Send us the motor nameplate, supply and control voltage, starting rate and accessory needs, and we check them against the ABB catalogue before quoting.

Attached is the PSR chapter extracted from ABB’s softstarter catalog 1SFC132012C0201, including order data, technical data and circuit diagrams. Quotations are prepared on request by Seven Star LLC, an independent supplier in Muscat, and this page shows no price or stock.