Zinsco / Sylvania SJK-3C-400 Molded Case Circuit Breaker
- 400A
- 3 Pole
- Bolt-On
Quantity
Zinsco / Sylvania SJK-3C-400 - 400A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Built for commercial and industrial facilities, the Zinsco SJK-3C-400 provides reliable overcurrent protection for legacy electrical distribution systems. This 3-pole, 400-amp molded case circuit breaker operates at up to 600VAC and utilizes a proven thermal-magnetic trip mechanism. It mounts into existing Sylvania, Challenger, Westinghouse, and Eaton panelboards, eliminating the need for complex retrofits. When a modern equivalent is required, the Eaton KD3400 serves as the substitute.Specifications
| Brand | Zinsco / Sylvania |
|---|---|
| Part Number | SJK-3C-400-R |
| Series | SJK |
| Amperage | 400A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 600VAC |
| Phase | 3 |
| AIC Rating | 65kA @ 240VAC, 30kA @ 480VAC, 22kA @ 600VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Sylvania Panelboards, Challenger Panelboards, Westinghouse Panelboards, Eaton Panelboards |
| Wire Gauge | (1) 3/0 AWG-500 kcmil (Al/Cu), (2) 3/0 AWG-250 kcmil (Al/Cu) |
| Max Wire | 500 kcmil |
| Min Wire | 3/0 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Adjustable Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Undervoltage Release, Lug Kits |
|---|---|
| Accessories | Lugs Not Included |
| Standards | UL 489, NEMA AB 1 |
| Approval | UL |
| Temp Rating | 40°C |
| Construction Features | Interchangeable Trip Unit |
Product FAQs
7 answersWhich panelboards accept the SJK-3C-400 circuit breaker?
This bolt-on breaker is designed for installation in legacy Sylvania, Challenger, Westinghouse, and Eaton panelboards that accommodate the SJK frame.
What are the lug wire size requirements for this breaker?
The terminals accept either a single conductor ranging from 3/0 AWG to 500 kcmil or dual conductors from 3/0 AWG to 250 kcmil per phase. Both aluminum and copper wiring are supported.
How does the adjustable magnetic trip function work on the SJK-3C-400?
The thermal-magnetic trip unit features a fixed thermal element for standard long-time overload protection, paired with an adjustable magnetic element that allows electricians to fine-tune the instantaneous short-circuit response.
What is the modern replacement for the obsolete Sylvania SJK-3C-400?
Because the Sylvania and Challenger SJK series is no longer manufactured, the Eaton KD3400 is commonly used as the modern substitute when replacing this 400A frame.
How does the interrupting rating scale with system voltage on this breaker?
The breaker provides a maximum interrupting capacity of 65kA at 240V AC. This rating decreases as system voltage increases, offering 30kA at 480V AC and 22kA at 600V AC.
Are Challenger SJK3C400 and Sylvania SJK-3C-400 the same breaker?
Yes, because of historical brand acquisitions, this 400A SJK frame was manufactured under both the Sylvania and Challenger brand names and shares the same physical dimensions and electrical characteristics.
What does the LI trip function code indicate on this SJK series breaker?
The LI designation means the trip unit provides Long-Time (L) and Instantaneous (I) protection. The long-time function handles sustained overloads, while the instantaneous function clears severe short circuits immediately.
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