ABB OA1G10 Auxiliary Contact

Full Name: ABB OA1G10 1NO Auxiliary Contact

Part No.: 1SCA022353R4970. Designed for right-hand mounting on ABB OT series disconnectors / load break switches. 1 Normally Open (1NO), early-make contact.

✅ Model Interpretation

OA: Auxiliary contact module

1: 1 contact set

G: Right-side mounting

10: NO Normally Open contact (OA1G01 = 1NC Normally Closed)

📋 Core Technical Data

🛠️ Compatible Switch Models

Suitable for ABB OT series load disconnectors: OT16 ~ OT4000, OTP, OTR, OTL, OTE

Installation note: Right-side mounting, maximum 2 OA1G series auxiliary contacts can be fitted. Used to collect ON/OFF status signals of disconnectors for PLC, indicator lights and interlock circuits.

📌 Application Scenarios

Disconnector position feedback in power distribution cabinets, MCC, PV combiner boxes, HVAC pump control cabinets

Safety interlock, cabinet door interlock, status indicator lamps, switch position acquisition for host system

Main power disconnector signal feedback for machinery

🧩 Series Comparison & Alternatives

1. OA1G01: 1NC (Normally Closed, right mounting)
2. OA7G10: 1NO (Normally Open, left mounting)
3. OA8G01: 1NC (Normally Closed, left mounting)

OA1G10AU: delayed version, do not confuse with standard model.

📦 Foreign Trade Information

HS Code: 85389099 (Electrical equipment parts), Origin: Bulgaria / Finland

ABB OA1G10 Auxiliary Contact Installation Manual (Compiled from ABB original document Doc.No.:1SCC390026M0018)

Product: OA1G10 1NO auxiliary contact, snap-fit right-side mounting for OT series disconnectors, early-make contact; Part No.:1SCA022353R4970

Compatible units: OT16~OT4000, OTP/OTR/OTL/OTE load disconnectors; related series: OA1G01 (right 1NC), OA7G10 (left 1NO), OA8G01 (left 1NC)

1. Safety Warnings
2. Installation must be performed by qualified electricians. Disconnect main power supply of the disconnector and verify zero voltage before work to prevent electric shock and arc burns.
3. Never plug or remove auxiliary contact module under energized condition.
4. Auxiliary contacts are only intended for control / signal circuits (AC-15), not for main power load.
5. After installation, manually operate the disconnector several times to verify contact operation logic.
6. Product Overview

Contact rating: 1NO (one normally open set), early-make (auxiliary contact closes in advance before main contacts of disconnector close)

Rated thermal current: Ith=16A; AC230V 6A / AC400V 4A / AC690V 2A

Mounting method: snap-fit, right side of disconnector. Max. 2 OA1G auxiliary contacts can be mounted side by side on one disconnector.

Terminal: M3.5 screw, recommended torque 0.8 Nm (7 lb.in)

Cable: 0.75～2.5 mm² copper conductor, stripping length 8～10 mm

III. Installation Steps

Precondition: Disconnector set to OFF position (0)

1. Locate mounting slot

Find the auxiliary contact guide rail on the right side of OT disconnector body. Left rail is only for OA7G/OA8G series, OA1G10 cannot be fitted on left side.

2. Snap module into place

Align guiding catches of OA1G10 with right rail, press evenly inward until a clear “click” sound is heard, confirming locking. Pull module slightly to confirm secure fixation.

Multiple modules: up to 2 units, snap in sequentially side by side on right rail.

3. Wire signal circuit

Strip insulation of control wire by 8–10mm, insert into terminal; tighten M3.5 screw to torque 0.8Nm.

Terminal marking: 1 and 2 are two terminals of NO contact.

Note: Do not use conductors larger than 2.5mm², poor terminal compression will occur.

4. Function verification

Manually operate disconnector handle:

ON position (I): OA1G10 NO contact closes; early-make feature: auxiliary contact conducts before main contacts close

OFF position (0): OA1G10 NO contact opens

Use multimeter continuity test on terminals to confirm correct logic.

5. Secondary protection check

Ensure wires are not pinched, no bare copper exposed on terminals; fit terminal cover of cabinet.

1. Removal Procedure
2. Cut off power of secondary signal circuit.
3. Set disconnector to OFF position 0.
4. Use small flat screwdriver to pry side catch of module, pull OA1G10 outward.
5. Loosen terminal screws and remove control wires.
6. Installation Limitations & Selection Rules
7. OA1G10 = Right mounting. Left-side status feedback requires OA7G10.
8. For one OT switch: max. 2 OA1G on right rail; max. 2 OA7G/OA8G on left rail.
9. No cross mixing: OA1G (right type) cannot be inserted into left rail. Mismatched mechanical structure may damage module and switch body by force.
10. OA1G10AU is delayed-travel version with different mechanical stroke; cannot directly replace standard OA1G10.
11. Commissioning & Troubleshooting

VII. Maintenance & Storage

1. Periodic inspection: Manually operate switch every 6 months, check contact operation and wiring tightness.
2. Storage environment: Clean and dry, temperature -25℃~+70℃, avoid condensation and dust.
3. Mechanical life: Matched with OT disconnector, typical 20000 operating cycles.

VIII. Original Document Reference

Original manual title: Installation Instruction Auxiliary contact OA1G01-OA1G10, OA7G10, OA8G01

ABB Document No.: 1SCC390026M0018

Applicable standards: GB/T 14048.5, IEC 60947-5-1

⚠️ Troubleshooting Summary

1. Contact failure: Verify full installation and handle travel; loose module catch is common fault.
2. Unstable signal: Check screw torque, wire size ≤2.5mm²; AC15 category, heavy load not allowed.
3. Selection reminder: OA1G10 is right-mounted only. OA7G10 for left-side feedback.

Key Installation Notes for ABB OA1G10 Auxiliary Contact

OA1G10: Right-mounted, 1NO early-make auxiliary contact for OT disconnectors, Part No.1SCA022353R4970

1. Pre-installation Check Items
2. Mounting side must be correct

OA1G10 only fits right guide rail of OT switch. Left rail only accepts OA7G10/OA8G01. Forced fitting on left side causes unlocked catch, failed plunger actuation or permanent damage.

2. Switch status confirmation

Install / remove only with OT disconnector at OFF position 0, main circuit and secondary signal circuit de-energized and verified. Hot plugging of auxiliary module is forbidden.

3. Check model timing characteristic

OA1G10 is early-make contact: auxiliary contact closes before disconnector main contacts. If interlock logic requires signal output only after main contact closure, this model is not suitable.

4. Quantity limit

Max. 2 OA1G modules (OA1G10 / OA1G01) can be stacked on right rail of one OT switch.

1. Mechanical Installation Details
2. Snap-fit feedback

Align module guiding ribs with right rail, press steadily inward until distinct “click” for locking. Pull module lightly after fitting to confirm no loosening.

Stack multiple modules: insert sequentially, keep modules closely fitted without gap.

2. Plunger inspection

After installation, inspect black actuating plunger of module. Plunger extends when switch OFF; plunger is pressed in during switch ON to trigger contact switching. Plunger shall not be skewed or stuck.

3. No hammering allowed

Do not strike module with screwdriver or hammer if insertion is difficult. Plastic housing or internal contact spring may break.

III. Secondary Wiring Details

1. Cable requirement

Copper wire 0.75～2.5mm²; stripping length 8~10mm. Overlong stripped insulation may cause short circuit between adjacent terminals; insufficient stripping leads to poor crimp.

2. Tightening torque

M3.5 terminal screw, standard torque 0.8 Nm. Low torque → intermittent signal under vibration; excessive torque → thread slipping and terminal base damage.

3. Terminal definition

Terminals 1 and 2 form NO contact, non-polarized passive dry contact. Not for high power load, utilization category AC-15.

Rating reference: AC230V 6A, AC400V 4A, AC690V 2A, for PLC, indicator lamps and interlock control circuits only.

1. Commissioning & Verification (Critical)
2. Multiple manual operation test

After installation, toggle OT switch ON/OFF for at least 3~5 cycles. Measure with multimeter continuity function:

OFF position 0: Terminal 1-2 open

ON position I: Terminal 1-2 closed (early-make: conduction occurs before handle fully reaches ON position)

2. Fault discrimination

No contact switching: mostly incomplete snap-fit, wrong mounting side;

Intermittent conduction: insufficient screw torque, loose copper strands;

Reversed logic: OA1G01 (NC) mistakenly selected.

1. Operation & Maintenance Restrictions
2. Auxiliary contact cannot be used as main circuit switch, only for position feedback and safety interlock signal.
3. For cabinets under heavy vibration, recheck screw torque and catch condition every 6 months.
4. Environment: Keep away from dust, condensation and corrosive gas to prevent contact oxidation and signal drift.
5. Removal: Power off first, pry side catch gently with flat screwdriver and pull out module. Never pull module by wires.
6. Common Misunderstandings

❌ Misunderstanding 1: OA1G10 can be mounted on either side → Not interchangeable, plunger geometry differs

❌ Misunderstanding 2: Auxiliary contact can drive heavy loads such as contactor coils → AC15 duty, limited load capacity

❌ Misunderstanding 3: Conduction occurs only when handle fully ON → Early-make design, conducts in advance, timing must be considered for interlock design

❌ Misunderstanding 4: Unlimited stacking of auxiliary contacts → Max. 2 units on right rail