Application Scenarios

At a regional water utility’s booster-pump MCC (the same utility we met in the 1SFB573002D1000​ soft starter and 2UBA002322R0010​ DI stories), three 15 kW submersible pumps were protected by a legacy trio: a 63 A Tmax XT2 (with 1SDA064796R1​ aux) → AF30 contactor → separate thermal-overload relay, all eating ~140 mm of DIN rail per pump plus a wiring jungle of jumpers. During a panel-rebuild to add a fourth pump on the same 600 mm gutter, the EPC’s first drawing kept the trio format and ran out of rail. The utility’s E&I lead pushed back and specified the 1SAM550000R1008​ (MS495-25) for each pump: the 45 mm body replaces breaker+contactor+OL in one slot, the rotary handle doubles as local DISCONNECT (lockable in OFF for LOTO), and the fixed 325 A magnetic clears a pump seizure short without nuisance during DOL start. The fourth pump squeezed in, the wiring dropped from 14 jumpers per branch to 4, and the “remote START” just lands on an external AF16 contactor coil (the 1SAM550000R1008​ doesn’t have a coil — it’s manual-only, so the AF16 handles PLC-driven auto-run). Post-cutover, the MCC room ran cooler (fewer devices dissipating), and the storeroom consolidated three spare SKUs into one 1SAM550000R1008​ plus AF16 coils. The 1SAM550000R1008​ turned a “we need a bigger MCC” problem into a re-terminal job.

 

Parameter

Main Parameters	Value/Description
Product Model	1SAM550000R1008​ (ABB MS495-25)
Manufacturer	ABB
Product Category	Manual Motor Starter / MMS (45 mm DIN series)
Rated Operational Current (Ie)	25 A (thermal adjustable range 17–25 A)
Rated Operational Voltage	Up to 690 V AC (650 V typical per catalog)
Magnetic Trip Setting	Fixed ~13×Ie ≈ 325 A (short-circuit protection)
Thermal Trip Class	Class 10A (adjustable dial 17–25 A) — Class 20/30 trip blocks swap-in available
Poles	3-pole
Short-Circuit Capacity (SCCR)	50 kA @ 400 V AC
Width	45 mm (DIN-rail)
Mounting	35 mm DIN rail (EN 60715)
Handle	Rotary ON/OFF/STOP, lockable in OFF (LOTO)
Certifications	IEC 60947-4-1, CE, CCC, UL 508
Compatible Aux	1SAM201000R1001 (aux contact, clip-on), 1SAM203000R1001 (signal contact)

 

Note: The 1SAM550000R1008​ = MS495-25 base device. ABB’s MS495 family also includes MS495-32 (22–32 A), MS495-40 (28–40 A), MS495-52 (40–52 A), MS495-70 (55–70 A) — all 45 mm width, same mechanical footprint, different thermal dial. Verify your motor’s FLA against the dial range before ordering; the magnetic trip is fixed at ~13×Ie across the family.

Technical Principles and Innovative Values

• Innovation Point 1: Three-Device Consolidation in 45 mm.​ A conventional motor branch at 25 A typically needs a 63 A MCCB (protection) + contactor (remote ON/OFF) + thermal OL relay (motor FLA protection) = ~120–150 mm of DIN rail, 3+ wiring jumps, 3 spare SKUs. The 1SAM550000R1008​ rolls all three into one 45 mm slot: the bimetal strip handles thermal OL (dial to motor FLA), the magnetic armature handles short-circuit (fixed 13×Ie), and the rotary handle is the manual disconnect. For a 12-pump MCC, that’s ~1.2 meters of rail saved — which is the difference between fitting and not fitting on a standard 600 mm gutter.
• Innovation Point 2: Fixed 13×Ie Magnetic — No Nuisance on DOL Start, No Blindness on Seize.​ Commodity MMS units sometimes let you adjust magnetic (which mechanics mess with), or fix it too low (nuisance on DOL inrush ~6–8×FLC). The 1SAM550000R1008​ locks magnetic at ~13×Ie — high enough to ride through a 7× DOL inrush on a healthy motor, low enough to clear a winding short or seized-rotor (which pulls 10–13× quickly) before the winding cooks. It’s the “set-and-forget” philosophy — once the thermal dial is set to FLA, there’s nothing else to tweak.
• Innovation Point 3: Clip-On Aux Without Wiring.​ The 1SAM550000R1008​ has a mechanical flag inside the rotary mechanism that drives clip-on aux contacts (1SAM201000R1001 = 1NO+1NC, snaps on left side, no screws, no wires to the moving parts). That NO/NC can land on the 2UBA002322R0010​ DI module (covered earlier) for “Motor Running / Motor Tripped” telemetry to the PLC — no separate auxiliary relay, no interposing, one cleaner MCC schematic. The aux also supports a signal contact variant (trip-alarm-only, doesn’t follow handle position) for SCADA “OL Trip” distinct from “Operator OFF.”

 

Application Cases and Industry Value

A food-processing chiller plant (the same one from the 1SFB573002D1000​ soft starter story) ran four 15 kW refrigerant compressors and six 5.5 kW condenser fans on a packed 800 mm MCC. The compressors were on 1SFB573002D1000​ soft starters (needed the ramp), but the fans were DOL — and each fan branch was the legacy trio (C32 MCB + AF09 + thermal OL) eating 135 mm of rail. When the plant added two more condenser fans for a capacity expansion, the EPC’s first drawing called for a new 400 mm gutter extension — ~€3.2 k in panel + labor. The plant E&I lead substituted the six existing fan branches and the two new ones to ABB 1SAM550000R1008​ MS495-25 (5.5 kW fans draw ~12 A at 400 V, so the 17–25 A dial covers them comfortably — yes, slightly oversized thermal range but acceptable per IEC 60947-4-1 for group motor sizes). The six+two branches collapsed from ~1.2 m to ~0.36 m of rail, the two new fans fit in the existing gutter, and the extension was cancelled. Post-cutover, the 1SAM550000R1008‘s rotary handle gave the refrigeration techs a local LOTO point per fan (previously they had to LOTO the MCB + tag the contactor — two-step, error-prone), and the clip-on aux landed “Fan Trip” on the 2UBA002322R0010​ DI slice for the first time. The plant manager’s math: panel extension cancelled (~€3.2 k saved), spare SKUs dropped from 3→1 per branch, LOTO step reduced from 2→1. The 1SAM550000R1008​ paid for itself in panel savings alone.In a second case, a packaging OEM standardizing 15 kW conveyor drives across its filler lines used the 1SAM550000R1008​ as the “branch protector” upstream of an AF16 contactor (PLC-controlled auto-run) and a 1SFB573002D1000​ soft starter (only on the heavy-start conveyors; light conveyors went DOL through the AF16). The OEM’s storeroom carried one 1SAM550000R1008​ for all 15 kW branches across three machine models — versus the old BOM which had C32 MCB (one SKU), AF16 (second), OL relay (third), thermal trip-block spares (fourth). Consolidating to the 1SAM550000R1008​ cut spare-line items by 75 % and eliminated the “installed wrong trip block” misfire that had caused two nuisance OL trips in Year 1.