Omron K8DS-PU2 — 3 Phase Undervoltage Monitor, 380 480 VAC
SKU: K8DS-PU2USD 23.00
17.5 mm slim 3-phase undervoltage, phase-sequence and phase-loss monitoring relay for 380–480 VAC supplies, one SPDT 5 A output
1-Year Warranty
Full manufacturer warranty
Global Shipping
Worldwide delivery available
Genuine Omron
100% authentic product
Ready to Ship
Usually ships within 24h
In Stock
This item is available for immediate shipment from our warehouse.
Contact for pricing, bulk discounts, and shipping
Product Overview
The Omron K8DS-PU2 is the 380–480 VAC variant of Omron's K8DS-PU slim monitoring-relay family, designed to protect three-phase loads from undervoltage, phase loss, and phase-sequence (incorrect phase rotation) faults on industrial control panels. manufactured by Omron Corporation. Hengyixin Automation stocks this controller in Xiamen and ships within 3-5 business days to most Asian, European, and North American ports.
In a 17.5 mm DIN-rail housing — the same width as a single MCB — it integrates a three-in-one monitor that, in the past, would have required three separate relays or a custom PLC logic block. Its single SPDT output (5 A at 250 VAC / 5 A at 30 VDC resistive) trips a contactor, sounds a horn, or signals the PLC when any of the three fault conditions is detected.
This is the classic wiring for a hard-wired protection circuit that operates even if the PLC is dead.
Key Features
- 380–480 VAC rated input
- Slim 17.5 mm DIN-rail housing — same width as one MCB
- One SPDT output relay, 5 A at 250 VAC / 5 A at 30 VDC resistive
- Higher inverter-noise immunity than older K8AK series
- SKU: K8DS-PU2
- Series: K8DS (Slim 17.5 mm monitoring relay)
- Voltage: 480 VAC
Best-Fit Applications
- Undervoltage trip on a 400 V chiller compressor to prevent low-voltage stall
- Phase-sequence and undervoltage protection on a 400 V conveyor motor in a bottling plant
- Phase-loss alarm on a pump station where a missing phase would damage the impeller
Buying Checklist
- Pick K8DS-PU2 for 380–480 VAC supplies; pick K8DS-PU1 for 200–240 VAC supplies
- Pick K8DS-AS1 if you need a dedicated asymmetry setpoint instead of undervoltage
- Pick K8DS-PU2 for 3-in-1 monitoring; pick K8DS-PH1 if you only need phase-sequence / phase-loss
Technical Specifications
| Model | K8DS-PU2 |
|---|---|
| Series | K8DS (Slim 17.5 mm monitoring relay) |
| Functions | Undervoltage, Phase loss, Phase sequence |
| Rated Input Voltage | 380 / 400 / 415 / 480 VAC, 3-wire 3-phase |
| Input Load | Approx. 2.8 VA |
| Undervoltage Setting Range | -30 % to +25 % of rated input voltage |
| Reset Value | 5 % of operating value (fixed) |
| Reset Method | Automatic |
| Undervoltage Operating Time | 0.1 to 30 s (adjustable) |
| Output Relay | 1 × SPDT, 5 A at 250 VAC / 5 A at 30 VDC resistive |
| Terminal Type | M3 screw |
| Mounting | DIN rail |
| Operating Temperature | -20 to +60 °C |
| Certifications | UL, CSA, CE, CCC |
Manufacturer documentation
Omron's own product page, where the manufacturer's current specification and lifecycle information are published. We are an independent distributor and cannot mirror those documents; the link goes to Omron's site.
FAQ for K8DS-PU2
What's the difference between K8DS-PU1 and K8DS-PU2?
Only the rated input voltage range. K8DS-PU1 covers 200/220/230/240 VAC three-phase supplies; K8DS-PU2 covers 380/400/415/480 VAC three-phase supplies. The functions (undervoltage, phase-loss, phase-sequence), output relay, and dimensions are identical. If your mains is 400 VAC nominal (Europe, most of Asia), pick the K8DS-PU2.
What's the difference between K8DS-PU2 and K8DS-PH1?
K8DS-PU2 monitors undervoltage + phase-loss + phase-sequence; K8DS-PH1 monitors only phase-loss + phase-sequence (no undervoltage threshold). If you only need to detect a missing or reversed phase without an undervoltage trip, the PH1 is cheaper and has a simpler setting. If you need full 3-phase protection including brownout detection, pick the PU2.
Can the K8DS-PU2 be used on a single-phase 230 VAC supply?
No — the K8DS-PU2 requires a three-phase 3-wire 380–480 VAC supply. For single-phase monitoring, use the K8AK-PA or K8AK-PW single-phase voltage monitor instead. For three-phase 200–240 VAC, use K8DS-PU1. Connecting the K8DS-PU2 to a single-phase supply will leave one terminal floating and the relay will not function correctly.
How long does the K8DS-PU2 take to detect phase loss?
0.1 s max. This is fast enough to protect most motors against the destructive heating that builds up within 1–2 seconds of running on two phases. The phase-sequence detection is 0.1 s ± 0.05 s. Power-ON lock time is 1 s ± 0.5 s, which means the relay ignores faults for the first second after power-on so it does not trip on the inrush of a large transformer or capacitor bank.
Similar Products
Explore related Omron models often viewed alongside this product.
