The Lincoln Electric 4-PACK RACK FLEXTEC 450 (K2956-2) is a factory-wired, multi-operator welding system that houses four Lincoln FLEXTEC 450 multi-process inverter welders on a single portable industrial rack. Designed for construction jobsites, shipyards, and large fabrication facilities, this rack system allows four welders to operate simultaneously from a single primary power drop, dramatically simplifying electrical installation and reducing cable runs on large projects. The complete system is NEC-compliant, IP23-rated, and ships with all four power sources installed and pre-wired to the main power distribution panel.
| Parameter | Value |
|---|---|
| Model / SKU | 4-PACK RACK FLEXTEC 450 / K2956-2 |
| Number of Power Sources | 4 × FLEXTEC 450 |
| Output per Welder (Rated) | 450 A / 38 V @ 60% duty cycle |
| Output per Welder (100% DC) | 400 A / 34 V |
| Input Power | 380–600 V, 3-phase, 50/60 Hz |
| Main Disconnect | 200 A, 600 V, 3-phase |
| IP Rating | IP23 / IP23S (model-dependent) |
| Processes per Welder | MIG (GMAW), FCAW, Stick (SMAW), DC TIG |
| Wire Feeder Compatibility | Analog across-the-arc and digital ArcLink feeders |
| Lifting | Two overhead lifting eyes |
| Fork Slots | Two forklift slots |
| Caster Option | Optional Caster Kit K2665-1 |
| Fusing | Individual fuses per power source for overcurrent protection |
| Standards | NEC-compliant; CE, UL, CSA per individual FLEXTEC units |
The 4-Pack Rack FLEXTEC 450 is built for multi-trade, multi-operator environments where running four individual primary drops would be cost-prohibitive or logistically complex:
- Heavy construction and structural steel — One power drop feeds four welders simultaneously on bridge, refinery, or high-rise structural packages.
- Shipbuilding and offshore platforms — IP23 weather resistance handles marine environments; portable rack footprint fits confined deck spaces.
- Pipeline and cross-country construction — Forklift slots and lifting eyes allow rapid repositioning as the work front advances.
- Industrial maintenance and turnaround — Full SMAW and FCAW capability for plant shutdowns requiring concentrated manpower.
- Large fabrication shops — Fixed-installation variant eliminates per-station electrical work; single-point disconnect simplifies lockout/tagout procedures.
Each FLEXTEC 450 inverter in the rack leverages Lincoln's multi-process inverter platform optimized for jobsite simplicity:
- Single Primary Power Drop — All four welders share one electrical connection to the main panel, reducing installation time and permit load per circuit.
- Factory-Installed and Pre-Wired — Power sources arrive mounted in the rack and connected to the internal power distribution panel — no in-field wiring of individual units.
- Individual Overcurrent Fusing — Each welder has an independent fuse, so a single overcurrent event does not interrupt the remaining three operators.
- Common Disconnect — A 200 A, 600 V, 3-phase master disconnect switch provides fast, single-point de-energization for the entire rack.
- Broad Voltage Acceptance — 380–600 V, 3-phase input covers US 460 V, Canadian 575 V, and international 380 V services without transformer modifications.
- IP23 Environmental Rating — Rated for outdoor use and light precipitation; designed for construction environments per IEC IP23 standards.
- Compact Footprint — Four 450 A welders in one rack occupy less floor or deck space than four individual machines with their own cabling.
The FLEXTEC 450 inverters in this rack are compatible with a wide range of wire feeder types, enabling flexible workstation configurations:
- Lincoln LN-25X with CrossLinc and TVT (K4267-4) — Preferred portable feeder for structural steel applications; CrossLinc eliminates voltage-compensation cables.
- Lincoln LN-25X Extra Torque (K4267-5) — Handles 3/32 in. cored wire for heavy plate passes.
- LN-15 and LN-22 across-the-arc feeders — For non-digital feeder setups in conventional SMAW/FCAW workflows.
- K2665-1 Caster Kit — Optional heavy-duty casters for relocating the complete rack on smooth concrete or plate flooring.
- Magnum PRO and Magnum 300/400 welding guns — Rated for 450 A output at rated duty cycle.
Browse the full line of Lincoln welding supplies and accessories at WeldingMart.
How many welders can operate simultaneously on the 4-Pack Rack FLEXTEC 450?
All four FLEXTEC 450 welders in the K2956-2 rack can operate simultaneously. The common power distribution panel is sized for concurrent full-load operation of all four units from one primary power drop.
What input voltage does the K2956-2 rack require?
The rack accepts 380–600 V, 3-phase, 50/60 Hz input. It is compatible with US 460 V, Canadian 575 V, and international 380 V three-phase services. Consult a licensed electrician to verify panel capacity before installation.
Is the 4-Pack Rack FLEXTEC 450 suitable for outdoor use?
Yes. All FLEXTEC 450 power sources are IP23-rated, meaning they are designed for operation in light precipitation and outdoor construction environments. The rack enclosure provides additional protection to the common wiring and distribution panel.
What is the duty cycle for each welder in the rack?
Each FLEXTEC 450 unit delivers 450 A at 60% duty cycle (38 V) and 400 A at 100% duty cycle (34 V). For continuous, uninterrupted welding, plan procedures around the 400 A / 100% rating.
Can I use the LN-25X wire feeder with the 4-Pack Rack FLEXTEC 450?
Yes. The FLEXTEC 450 is compatible with across-the-arc feeders like the LN-25X. For CrossLinc-enabled voltage control without additional cables, use the LN-25X K4267-4 or K4267-5 models specifically paired to each FLEXTEC 450 output.
Does the rack include casters?
Casters are optional on the K2956-2. The Optional Caster Kit K2665-1 can be ordered separately for applications requiring rack mobility on smooth surfaces. Standard configuration includes two overhead lifting eyes and two forklift slots for crane or forklift positioning.