Power Adapters & SPD
Installation Guide
DIN rail mounting, SPD wiring, power adapter wiring, and load calculation for HPzenAi power adapters and SPDs.
Installation Video Guide
Watch the complete installation walkthrough before starting. The video covers DIN rail mounting, SPD wiring, adapter wiring, and 12V bus distribution.
Tools Required
Gather these tools before starting. All wiring inside the electrical panel must be performed by a qualified electrician.
Tool Checklist
| Preview | Quantity | Item | Details |
|---|---|---|---|
| × 1 | Flat-Head Screwdriver | For tightening terminal block screws on the adapter, SPD, and bus bar connections | |
| × 1 | Wire Strippers | To prepare cable ends before insertion into terminal blocks | |
| × 1 | Multimeter | To verify 12V DC output voltage at the bus bar before connecting field devices | |
| × 1 | DIN Rail Cutters or Hacksaw | To cut 35 mm DIN rail to length if a new section is being installed | |
| × 1 set | Cable Ferrules and Crimper | For neat, reliable terminal connections on stranded copper cable |
Flat-Head Screwdriver
For tightening terminal block screws on the adapter, SPD, and bus bar connections
Wire Strippers
To prepare cable ends before insertion into terminal blocks
Multimeter
To verify 12V DC output voltage at the bus bar before connecting field devices
DIN Rail Cutters or Hacksaw
To cut 35 mm DIN rail to length if a new section is being installed
Cable Ferrules and Crimper
For neat, reliable terminal connections on stranded copper cable
What's in the Box
Verify all items are present before beginning installation.
Included Items
| Preview | Quantity | Item | Details |
|---|---|---|---|
| × 1 | Power Adapter Unit | DIN rail-mounted AC-to-DC or DC-to-DC converter with AC input and 12V DC output terminal blocks | |
| × 1 | DIN Rail Mounting Clip | 35 mm DIN rail clip integrated into the adapter body | |
| × 1 | Installation Guide | Printed quick-reference card for wiring and load calculations |
Power Adapter Unit
DIN rail-mounted AC-to-DC or DC-to-DC converter with AC input and 12V DC output terminal blocks
DIN Rail Mounting Clip
35 mm DIN rail clip integrated into the adapter body
Installation Guide
Printed quick-reference card for wiring and load calculations
Load Calculation — Sizing the Adapter
Calculate the total 12V DC load before selecting and wiring the adapter. Exceeding the rated output causes voltage drop and overheating.
Steps
- HPzenAi Gateway: approximately 3W (0.25A at 12V).
- Relay Controller: approximately 2W per active output channel (0.17A per channel).
- Energy Meter (EM-1P-60A or EM-3P-60A): approximately 1W (0.08A) each.
- Water Meter (RS485 model): approximately 1W (0.08A) each.
- PWR-1P-12V-15W provides 15W (1.25A) — suitable for a gateway plus up to four field devices.
- PWR-3P-12V-12W and PWR-SOL-12V-12W provide 12W (1.0A) — suitable for a gateway plus two field devices.
- For larger installations, install multiple adapters on separate 12V bus segments rather than overloading a single unit.
SPD Installation (Recommended)
Install the SPD at the AC supply entry point, immediately before the power adapter. The SPD absorbs surge energy before it reaches the adapter and all downstream IoT electronics.
Steps
- Snap the SPD onto the 35 mm DIN rail at the beginning of the DIN rail run, before the power adapter.
- For SPD-1P (single-phase): wire the incoming Line (L) through the SPD input and take the SPD output to the adapter AC input terminal.
- Wire Neutral (N) directly to the adapter — Neutral does not need to pass through the SPD-1P.
- For SPD-3P (three-phase): wire R, S, T through the SPD inputs and take the SPD outputs to the adapter AC input terminals.
- Connect the SPD earth terminal to the panel protective earth (PE) bus bar — this earth connection is essential for surge current to dissipate safely.
- Tighten all SPD terminal screws to the specified torque — loose connections reduce surge protection effectiveness.
- Check the SPD status indicator after installation — a green indicator confirms the SPD is functional.
Power Adapter Wiring
Wire the AC input from the SPD output and connect the 12V DC output to a bus bar for distribution to field devices.
Steps
- Snap the power adapter onto the 35 mm DIN rail next to the SPD.
- For PWR-1P-12V-15W: connect L from the SPD output to the adapter AC-L input terminal; connect N to the adapter AC-N input terminal.
- For PWR-3P-12V-12W: connect R, S, T from the SPD-3P outputs to the adapter R, S, T input terminals.
- For PWR-SOL-12V-12W: connect the solar battery positive (+) to the adapter DC+ input and negative (−) to DC− input — observe polarity carefully.
- Connect the adapter DC output: 12V+ to the panel's 12V positive bus bar; GND to the negative bus bar.
- Use minimum 1.0 mm² cable for the 12V output and bus bar connections.
- Distribute 12V from the bus bar to each IoT device using minimum 0.5 mm² cable.
Commissioning & Verification
After wiring, verify the 12V output before connecting field devices.
Steps
- Apply AC supply power and confirm the adapter's green LED or power indicator is lit.
- Measure 12V DC between the positive and negative bus bar terminals using a multimeter — expect 11.8V to 12.5V.
- If voltage is below 11V, check for overloading — disconnect field devices one at a time to identify the cause.
- Connect field devices to the 12V bus bar one at a time and verify each device powers on correctly.
- Check the SPD indicator remains green — a red indicator means the SPD has absorbed a surge and must be replaced.
- Confirm the adapter body is not excessively hot after 30 minutes of operation — overheating indicates the adapter is overloaded.
Installation Checklist
Use this checklist before handing over the installation.
Steps
- SPD installed before the adapter on the DIN rail.
- SPD earth terminal connected to panel PE bus.
- SPD status indicator is green.
- Adapter snapped securely onto DIN rail.
- AC input wiring from SPD output to adapter — L, N (and R, S, T for three-phase).
- 12V DC output wired to positive and negative bus bars.
- Bus bar voltage verified: 11.8V to 12.5V DC.
- All field devices powering on correctly.
- Adapter not overheating after 30 minutes.
- No exposed conductors or loose terminal screws.
Important Installation Notes
Follow these precautions during installation and ongoing maintenance.
Steps
- All panel wiring must be performed by a qualified electrician in accordance with local electrical codes.
- Isolate the panel AC supply before wiring the adapter or SPD.
- Replace the SPD immediately if its status indicator turns red — a triggered SPD no longer provides protection.
- Do not exceed the adapter's rated output current — fit an additional adapter if the 12V load grows beyond the rated power.
- Ensure adequate panel ventilation — DIN rail adapters generate heat and require airflow for rated performance.
- Inspect terminal screws annually and re-tighten any that have worked loose due to thermal cycling.