1. Standard Electrical Control Cabinet Photos (Contactor + Thermal Overload Relay Solution)
The photo shows a typicalstar-delta starting control cabinet(for a 55kW motor): inside the cabinet, from top to bottom — main circuit breaker (NSX160F), three AC contactors (LC1D80 main contactor + LC1D40 star + LC1D40 delta), thermal overload relay (LRD32), control circuit fuses, pushbuttons and indicator lights. The door is fitted withstart/stop pushbuttons + run indicator light, standard hardwired logic.
2. VFD Panel Photos (VFD + Braking Unit Solution)
The photo shows a22kW VFD panel: the core component is a Siemens G120 VFD (6SL3210-1KE27-0UF0), with a braking resistor (400Ω/2kW) and braking unit. Internal layout — VFD centered in the upper section, main circuit breaker + contactor (for bypass) in the lower section, control terminal blocks on the right. The VFD has≥150mm heat dissipation clearanceabove and below, and a cooling fan is mounted on the cabinet top.
3. Soft Starter Cabinet Photos (Thyristor Soft Starter + Bypass Solution)
The photo shows a75kW soft starter cabinet: the core is a Schneider ATS480 soft starter (75kW), with a bypass contactor (LC1D115). During startup, the thyristors ramp the voltage; after startup completes, the bypass contactor closes and the thyristors drop out of the circuit.After bypass, the main circuit has no harmonics, which is one advantage of soft starter cabinets over VFD panels. The door is fitted with an ammeter + startup time setting knob.
4. Comparison of three control cabinet types (differences visible in the photos)
| Comparison | Standard control cabinet | VFD panels | Soft starter cabinet |
|---|---|---|---|
| Core components | Contactor + thermal overload relay | VFD + braking resistor | Soft starter + bypass contactor |
| Speed control | None | Yes (stepless, 0–50 Hz) | None (reduced-voltage start only) |
| Heat dissipation inside the cabinet | Natural convection | VFD runs hot — fan required | Low heat after bypass |
| Footprint (55 kW) | 800×400×1800mm | 800×400×2000mm | 600×400×1800mm |
| Typical cost | Lowest | Highest | Moderate |
5. Judging control cabinet quality from photos (6-point visual inspection standard)
① Neat wiring: wire duct runs straight and free of crossovers;② Wire markers: heat-shrink printed, legible and consistent;③ Component spacing: contactor spacing ≥50 mm for heat dissipation and wiring access;④ Grounding: dedicated PE bar; cabinet door grounded with braided copper strap;⑤ Nameplates: every component has a unique ID that matches the drawing;⑥ Sealing: cable glands sealed at entries and exits; cabinet gasket intact.
FAQ FAQ
What is the difference between electrical control cabinet and distribution cabinet photos?
In distribution cabinet photos, focus onbusbars and circuit breakers(high current, heavy copper bar); in control cabinet photos, focus onContactors and control circuits(low current, multiple wire ducts). Distribution cabinets are "coarse"; control cabinets are "fine".
What are the white labels with black text on the control cabinet photos?
It is aheat-shrink wire markers, printed with the component code and wire number (e.g., 1-Q1:3), with the same number at both ends so a fault can be traced by number.
What is the large metal block in the VFD panel photo?
It is abraking resistor(400Ω/2kW), used to absorb the regenerative energy when the motor decelerates and prevent DC bus overvoltage in the drive. High-power drives also include a braking unit.
What are the blue blocks on the control cabinet photo?
Usuallyinterposing relays(such as Omron MY2NJ), with DC24V coils, used for isolation and amplification between PLC outputs and contactor coils.
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