Square D 997318 Molded Case Circuit Breaker
- 150A
- 3 Pole
- Bolt-On
Quantity
Square D 997318 - 150A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Built for heavy-duty commercial and industrial environments, this 150A molded case circuit breaker delivers robust thermal-magnetic protection. The three-pole device is specifically designed to mount into legacy Square D ML panelboards, serving as a reliable replacement for aging infrastructure. It accommodates 4 AWG to 300 kcmil wire and provides fixed long-time and instantaneous (LI) trip functions. The breaker ensures system safety with a 10kAIC interrupt capacity at 600VAC.Specifications
| Brand | Square D |
|---|---|
| Part Number | 997318-R |
| Series | 99 Series |
| Amperage | 150A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 600VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 600VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Square D ML Panelboards |
| Wire Gauge | 4 AWG-300 kcmil (Al/Cu) |
| Max Wire | 300 kcmil |
| Min Wire | 4 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch |
|---|---|
| Accessories | Load Side Lugs Included |
| Standards | UL 489, NEMA AB-1 |
| Approval | UL, CSA |
| Temp Rating | 40°C |
Product FAQs
5 answersWhat type of panelboard is the Square D 997318 designed to fit?
This 3-pole molded case circuit breaker is specifically designed for installation in legacy Square D ML panelboards.
Is the Square D 997318 an active or legacy circuit breaker?
This model is part of the legacy 99 Series, sometimes referred to as Type 997 or ML-3. It is considered obsolete by the manufacturer and is primarily used as a direct replacement for aging infrastructure in existing ML panels.
What wire sizes and materials are compatible with the lugs on this 150A breaker?
The factory lugs accept wire gauges ranging from 4 AWG to 300 kcmil. They are rated for use with both aluminum and copper (Al/Cu) conductors.
What does the LI trip function code indicate on the 997318?
The LI designation means this thermal-magnetic breaker features fixed Long-Time and fixed Instantaneous trip functions to protect against overloads and short circuits.
What safety precautions should be taken when installing this bolt-on breaker in a legacy panel?
Always ensure the panelboard is fully de-energized before installing or removing bolt-on breakers. Verify that the busbars in the legacy ML panel are clean, free of pitting, and properly torqued to ensure a secure connection.
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