ABB OT25F6 Switch-Disconnector

Numéro de commande: 1SCA104880R1001, Made in Finland. Handle and shaft are NOT included; operating accessories must be ordered separately.

Explication du code modèle

OT: OT-series load-break switch-disconnector

25: Rated operational current 25 A

F: Front-operated; compatible with base-screw mounting and DIN-rail mounting

6: 6-pôle (6P.)

Spécifications électriques de base

Dimensions mécaniques

Width × Height × Depth: 70 × 68 × 68 mm. Incoming/outgoing cables can be wired top-in-bottom-out or bottom-in-top-out.

Montage & Accessoires

1. Options de montage: DIN35 rail clip-on mounting + base screw fastening
2. ⚠️Handle and operating shaft are not supplied with the base unit. Handle assemblies (par exemple. OHS series) must be purchased separately for operation; door-mounted external operation is supported.
3. Auxiliary contact blocks (OA1G series) can be fitted as optional add-ons.
4. Padlockable in OFF position for safe maintenance isolation.

Applications typiques

Multi-circuit AC/DC isolation for PV combiner boxes, energy-storage systems and UPS

Maintenance disconnector inside control cabinets for frequency converters and soft-starters

6-configuration des pôles: 3-phase + 3-DC-circuit isolation, dual 3-phase isolation scenarios

Équivalent & Replacement References

Original ABB: Only OT25F6 base unit; Do not confuse with OT25FT6 (FT = door-mount type)

Référence alternative nationale: CHINT NH2-25-6P, Delixi 6P-25A disconnector (verify mounting dimension and terminal capacity before substitution)

Pièges courants

1. OT25F6 is delivered as base unit only. No handle is provided; direct manual actuation is impossible. Handles are frequently omitted in project ordering.
2. Do not mix F (base / Montage sur rail DIN) and FT (door-mount) variantes. They are mechanically non-interchangeable.
3. Current derating is required for motor-load operation under AC-23A utilization category.

Operating Instructions for ABB OT25F6 (OT-Series) Switch-Disconnector

⚠️Important note: OT25F6 base unit is fitted with a square drive shaft bore only. No handle or shaft is factory-fitted. OHS / OHB handle assemblies must be installed before operation. Never turn the bare shaft bore directly.

Two Handle Types

1. Internal cabinet direct handle (OHS): Mounted on the front face of the switch body for operation inside the enclosure.
2. External door-mount handle (OHB / OHYS): Used with extended square shaft; handle fitted to cabinet door surface. Equipped with door-interlock: Cabinet door cannot be opened when switch is ON (energized state). Door can only be opened when switch is switched OFF.

Standard Manual Close / Open Operation

Close (SUR, energize circuit): Rotate handle clockwise until an audible “click” locks the mechanism. Align handle marker to I / ON position to ensure full contact closure.

Ouvrir (DÉSACTIVÉ, isolate circuit): Rotate handle counter-clockwise until an audible “click” locks the mechanism. Align handle marker to 0 / OFF position to establish safe isolating gap.

✅Always rotate to full locked position. Intermediate positions will cause poor contact and overheating.

CŒUR (Lockout-Tagout) for Maintenance

Locking is only possible at the OFF position (locking in ON position is not supported).

1. Turn handle fully to OFF position.
2. Flip up the padlock hasp on the handle.
3. Fit padlocks (maximum. 3 padlocks simultaneously, padlocks supplied by end-user). The handle is mechanically locked against rotation for energy isolation during maintenance.
4. Unlock: Remove padlocks, reset the hasp, then resume operation.

Auxiliary-Contact Signalling (Optional OA1G Accessory)

With auxiliary-contact block fitted:

When switch turns ON, auxiliary-contact state changes, providing position feedback signal to PLC or indicator lamps.

Auxiliary contacts follow mechanical switch position, independent of main-circuit voltage presence.

Operational Safety Notes

1. OT switch-disconnectors can switch rated load under AC-21A duty. Derate current for motor-load AC-23A applications. It cannot break short-circuit currents; fuses or circuit-breakers must be installed upstream.
2. Never force a jammed handle. If handle sticks, de-energize equipment and investigate mechanical obstructions.
3. For door-interlock versions: Inability to open door while ON is normal safety feature. Do not pry door open forcibly. Always switch OFF before opening cabinet for maintenance.
4. This device provides isolation function only. Always verify zero-voltage before maintenance work, even if switch is OFF.
5. Cable-in / cable-out direction can be reversed (top-in-bottom-out or bottom-in-top-out) without changing operating logic.

Common Operational Symptoms

Défauts courants & Troubleshooting for ABB OT-Series Switch-Disconnectors (including OT25F6)

Safety Warning: All maintenance work must be performed with power disconnected and LOTO lockout applied. The OT-series base unit cannot be disassembled for repair. Replace complete unit if internal contacts or mechanism are damaged. Do not open the housing.

1. Stiff / Jammed / Hard-to-rotate handle

Frequent mistake: Never twist bare square-shaft bore on base unit without handle fitted; internal mechanism will be destroyed.

2. No-load output, phase-loss or intermittent conduction with handle in ON position

3. Overheating of switch body / hot terminals / burning odour

4. Output-side remains energized in OFF position (loss of isolation)

5. Door-interlock malfunction (OHB external-door handle)

6. Missing or reversed signal from fitted OA1G auxiliary contacts

7. LOTO padlock function fails; cannot lock at OFF position

8. Abnormal DC-circuit performance (PV / energy-storage applications)

Symptôme: Severe arcing during opening-closing operations

Cause: Standard OT-F AC-rated switch-disconnector has limited DC breaking capacity. For high-voltage DC circuits, select dedicated OTDC DC-rated switch-disconnectors. Do not use standard OT25F6-6P for repeated DC load-breaking duty; contact erosion will occur.

Routine Maintenance Guidelines for OT-Series Switch-Disconnectors

1. Carry-out visual inspection every 6 months: Check terminals for discoloration / surchauffe, verify smooth handle operation. Avoid intermediate operating positions.
2. Do not clean plastic housing with liquid or solvent agents; wipe dust with dry cloth only.
3. Never disassemble switch housing. Replace complete unit for internal-contact or mechanism damage.
4. Switch-disconnector cannot interrupt short-circuit faults. Fuses or circuit-breakers must be installed upstream.

Installation Notes for ABB OT-Series Switch-Disconnector (OT25F6)

Applicable to OT-F (du rail / base-mount) gamme. All installation work shall be performed de-energized with voltage verification by qualified electricians. Handle and shaft are not supplied with base unit and must be ordered separately; this is the most-frequently-made error.

1. Installation mécanique
2. Méthodes de montage
3. DIN35 rail mounting: Clip onto DIN rail and engage bottom latch fully to prevent vibration-induced detachment.
4. Base-plate screw mounting: Utiliser des vis M4; tighten diagonally. Do not over-stress housing by one-sided fastening.
5. Orientation de montage: Verticale, horizontal or ceiling-mount (inverted) installation is permissible; performance remains unchanged.
6. Model differentiation:

OTxxF: Unit mounted on DIN-rail / base-plate; compatible with internal-cabinet OHS handle or external-door-mount OHB handle.

OTxxFT: Door-mount type; unit directly fitted to cabinet door panel. Mechanically non-interchangeable with OTxxF.

2. External-door-mount handle (OHB / OHYS) + extended square-shaft installation
3. Cut extended-shaft to accurate length. Maintain 2-3 mm axial clearance after assembly. Excess-length shaft jams mechanism; too-short shaft causes drive disconnection and loss of operation.
4. Verify door-interlock function after assembly: Door shall not open when ON; door can open only when OFF. If interlock fails, adjust shaft insertion depth; never forcibly pry cabinet door.
5. After handle installation, confirm position markers on switch body and handle are synchronized; no positional offset.
6. Fitting Auxiliary-Contact Block (OA1G)
7. Clip auxiliary-contact block sideways into unit until positive latching click is heard. Poor seating causes signal loss.
8. Auxiliary-contact terminal tightening torque: 0.4-0.8 N·m. Excessive torque will crack small-size terminal housing.
9. Câblage électrique (OT25F6)
10. No mandatory cable-entry direction: Top-in-bottom-out or bottom-in-top-out wiring are both acceptable.
11. Spécification du conducteur: 0.75-10 mm² copper conductors. Use wire ferrules for multi-stranded flexible cables; avoid exposed loose strands that may cause short-circuit.
12. Couple de serrage des bornes: 2.2 N·m. Use torque-wrench; do not rely on hand-feel. Low torque causes thermal overheating; over-torque fractures terminal housing.
13. Refit terminal protective covers after wiring to maintain IP20 touch-safety protection.
14. Switch-disconnector cannot break short-circuit current. Fuses or circuit-breakers must be fitted upstream.
15. Derate current for motor-load circuits under AC-23A utilization category.

III. Installation for DC Applications (PV / Energy-Storage)

1. Standard OT-F AC-rated switch-disconnector has limited DC breaking performance. For high-voltage DC circuits, select dedicated OTDC DC-rated switch-disconnectors. Do not repeatedly break DC load-current using OT25F-6P; arcing will erode contacts.
2. Strictly observe positive-/negative-polarity wiring according to datasheet for DC-circuit connections.
3. Conditions environnementales
4. Température ambiante de fonctionnement: -25 ℃ ~ +60 ℃. Current derating required above +40 ℃.
5. Altitude rating: ≤ 2000 m. Derate insulation and current for installation altitude > 2000 m.
6. Enclosure minimum protection class IP20. Évitez les fortes poussières, metallic particles, corrosive gas and condensation. Install enclosure heaters under condensing conditions to prevent creepage and insulation degradation.
7. Do not expose unit to outdoor weather or rain.
8. Commissioning Checks After Installation
9. Perform multiple full ON-OFF cycles. Confirm crisp latching action, smooth movement, no intermediate detent positions.
10. LOTO lockout test: Verify padlock can be fitted at OFF position; handle becomes locked against rotation.
11. Auxiliary-contact test: Measure signal correctness during ON / OFF switching cycles.
12. Pre-energization test: Insulation-resistance measurement between poles and to earth.
13. Energized commissioning: Periodically inspect terminals for abnormal temperature rise.
14. Pratiques interdites
15. ❌Do not rotate bare square-shaft bore without handle fitted; internal mechanism damage will occur.
16. ❌Do not disassemble switch housing. Replace complete unit for internal-mechanism damage; field repair is not permitted.
17. ❌Do not use switch-disconnector as short-circuit protective device in place of circuit-breaker.
18. ❌Do not force jammed handle. De-energize and investigate mechanical causes.
19. ❌Prevent metallic debris from falling inside switch body during installation, which may result in internal short-circuit or jamming.

VII. Summary of Typical Installation Errors