water pump protector
A water pump protector is an electronic circuit that stops the pump before the pump is damaged.
What is a water pump protector?
A water pump protector is an electronic circuit that stops the pump before the pump is damaged.
HYDROSET PM821 detects three dangerous conditions and stops the pump in each: dry running (when no water reaches the pump, seen either as current falling below F4 or as pressure failing to reach F10), over current (when the pump current rises above F3), and a rise in the unit's internal temperature. Each condition shows a fault code on the display, and the dry-running faults retry on their own every F6 minutes.
Types and other names
Other names for this device: smart pump controller · automatic pump switch · pump protector · electronic pressure switch · pressure controller
How it works
- The pressure sensor measures the line pressure continuously.
- When the pressure falls to the F2 value, the unit soft-starts the pump.
- When the pressure reaches the F1 value, the unit soft-stops the pump.
- If the pump current rises above F3, or no water arrives, the unit stops the pump and shows a fault code.
Model selection guide
| Pump current | Pump power | Model | Typical use |
|---|---|---|---|
| up to 8 A | up to 1.5 kW | PM821-8 | 1–4 floors, homes and shops |
| 8 – 16 A | up to 3 kW | PM821-16 | 5–10 floors, booster sets |
| up to 25 A | up to 4 hp | PM821-25 | Residential, commercial and agricultural |
The current on the pump nameplate decides the model, nothing else.
Compared with models on the market
Pump controllers are sold in Iran under many names. The table below lists only the verifiable properties of PM821 taken from its manual. No figure and no price is given for any other product, because market prices change quickly and an unsourced claim damages the text's credibility.
| Property | PM821-8 | PM821-16 | Unit |
|---|---|---|---|
| Maximum pump current | 8 | 16 | A |
| Maximum pump power | 1.5 | 3 | kW |
| Peak starting current | 10 | 30 | A |
| Supplied sensor pressure range | 0 – 20 | 0 – 20 | bar |
| Pressure sensor thread | G1/4 | G1/4 | female |
| Input voltage | 180 – 240 | 180 – 240 | V |
| Output voltage | — | — | equal to input |
| Unit's own consumption | < 5 | < 5 | W |
| Operating temperature | -15 – 55 | -15 – 55 | °C |
| Weight, boxed | 650 | 650 | g |
These figures come from the HYDROSET PM821 user manual (hardware A3.3, software 4.0). The manual covers PM821-8 and PM821-16 only, so no column is shown for PM821-25.
Common brands on the market: استریم · JCP · پنتاکس · لوئیز · دلتا / ونزو / وات · آبارا / رویال
Applications
Price and ordering
The price of PM821-8 and PM821-16 is on each product page. PM821-25 is made to order and has no published price; contact the company for it.
Frequently asked questions
What is a water pump protector?
A water pump protector is an electronic circuit that stops the pump before the pump is damaged. HYDROSET PM821 detects three dangerous conditions and stops the pump in each: dry running (when no water reaches the pump, seen either as current falling below F4 or as pressure failing to reach F10), over current (when the pump current rises above F3), and a rise in the unit's internal temperature. Each condition shows a fault code on the display, and the dry-running faults retry on their own every F6 minutes.
Which PM821 model suits my building?
The current on the pump nameplate decides it: up to 8 A and 1.5 kW is PM821-8, 8 to 16 A and up to 3 kW is PM821-16, and up to 25 A is PM821-25.
Does it work without a pressure vessel?
Yes. HYDROSET PM821 works both with and without a pressure vessel.
Last updated: