DEIF PPU-3 – Generator Paralleling & Protection Unit for Reliable Switchboard Control

DEIF’s PPU-3 is a compact protection and synchronising controller designed for generator sets and mains-parallel applications. From my experience, it’s a solid choice when you need dependable automatic synchronising, breaker control, and a well-rounded protection suite without building a big relay panel from scratch. You might notice that it reduces wiring complexity, makes commissioning predictable, and typically plays nicely with existing CT/VT measurement and standard breaker coils.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days
• Delivery time: 1 week if in stock; no more than one month at the latest
• Payment terms: 50% advance payment; full payment prior to delivery
• Express delivery: FedEx, UPS, DHL

Key Features

• Automatic synchronising & sync-check: Handles live bus and dead-bus conditions with precise breaker close commands.
• Integrated generator protection: Typically includes over/under voltage and frequency, reverse power, and overcurrent functions for safe operation.
• 3‑phase measurement via CT/VT: Direct connection to current transformers and potential transformers for accurate metering and protection.
• Flexible I/O and relay outputs: Digital inputs for status and permissives; form‑C relay outputs for breaker control and alarms.
• Modbus connectivity: RS‑485 (Modbus RTU) for SCADA/BMS integration—handy for remote supervision and trending.
• Panel‑mounted HMI: Clear front panel with indicators/keys, making local setup and status checks straightforward.
• Rugged 24 VDC supply: Suited for switchboard environments with stable operation across typical control voltages.

Technical Specifications

Application Fields

The PPU-3 fits well in generator switchboards where safe paralleling and robust protection are non‑negotiable. Typical scenarios include:

• Diesel and gas genset paralleling (island mode and mains parallel)
• Prime power plants and IPP rental fleets needing quick setup
• Hospitals, data centers, and airports with stringent switching sequences
• CHP and microgrid projects with utility tie-in
• Marine and offshore switchboards (approvals vary by variant)

A utilities client told us they swapped it in for an aging relay set and had commissioning wrapped up in under a day—no surprises on CT ratios or sync logic, which tends to be where time goes.

Advantages & Value

• Reliability you can measure: Integrated protection and sync logic reduce interwiring errors versus discrete relays.
• Compatibility: Works with standard CTs/VTs and common breaker coils, so retrofit risk is lower in many cases.
• Cost‑effective panels: Fewer devices and smaller door cut‑outs mean leaner switchboard layouts.
• Data visibility: Modbus integration gives your SCADA or BMS direct access to measurements and alarms.
• Support & lifecycle: Stable firmware and a clear parameter structure make future changes less painful.

Installation & Maintenance

From my experience, most issues come from wiring and earthing rather than the controller itself. A few practical guidelines:

• Panel standards: Install in a ventilated, dry switchboard (typ. IP54 or better for harsh sites). Keep control wiring segregated from power cabling.
• CT/VT wiring: Observe polarity (P1/P2, S1/S2) and short CT secondaries before handling. Verify burden is within the device’s limits.
• Grounding & EMC: Use a single‑point reference ground and shielded twisted pairs for comms. Route cables away from VFDs where possible.
• Breaker control: Confirm closing/ tripping coil voltage and interlock signals. Test sync‑check permissives at low risk first.
• Routine maintenance: Annual function test of protections (UV/OF/RP/OC), clean the front panel, back up parameters, and apply firmware updates when qualified.

Common supporting components: suitably rated CTs/VTs, motorised breakers (A/AR), RS‑485 gateway or converter, and governor/AVR interface leads.

Quality & Certifications

• CE marking and RoHS compliance are typically provided by the manufacturer
• Designed in line with relevant IEC protection standards (e.g., IEC 60255 family)
• UL/Marine approvals may be available on specific variants; documentation can be supplied upon request
• Manufacturer quality management commonly certified to ISO 9001
• Warranty: 365 days

If you’re consolidating older protection relays and a separate synchroscope/synchroniser, the DEIF PPU-3 seems to be a practical step up—cleaner wiring, quicker FAT, and easier remote supervision. We can help size the CT/VT ratios and set the sync window based on your breaker timing and grid code.