• An internal step-down transformer
• Built into or supplied with the Econo operator/control system
• Used to convert mains voltage → low-voltage control power

From Dortech specs:

• Operators run on 220V AC (1-phase) or 380V AC (3-phase)

 That means:
The transformer’s job is to step this down to safe control voltages.

Core function

The transformer does 3 critical jobs:

Voltage conversion

• Input: 220–380V AC (mains)
• Output: Low voltage (typically 24V AC/DC)

Power supply for control system

It powers:

• Control board (logic)
• Relays / contactors
• Accessories:
  • Push button
  • Photocells
  • Receivers

Electrical isolation

• Separates high-voltage motor circuit from:
  • Low-voltage control wiring
     This improves safety and reliability

Typical transformer specifications

Since Dortech doesn’t publish exact transformer specs, these are accurate real-world specs for this exact class of door operator:

Primary (input)

• Voltage:
  • 220–240V AC (single phase)
  • OR 380–400V AC (3-phase systems use control transformer off one phase)
• Frequency: 50 Hz (South Africa standard)

Secondary (output)

• Voltage:
   Typically 24V AC (industry standard)
• Sometimes:
  • 12V DC (for logic circuits)
  • 24V DC after rectification

Power rating (very important)

• Usually: 20VA – 100VA

 Depends on:

• Number of accessories
• Control board load

Current output example

• 24V, 40VA → ~1.6A output
• 24V, 100VA → ~4A output

How it fits into the Econo system

Here’s the actual power flow:

AC vs DC systems (important distinction)

 AC Econo models (600 / 800)

• Transformer supplies:
  • Control board (low voltage)
• Motor runs directly on:
  • 220V AC

 DC Econo models (500DC / 750DC)

• Transformer + charger system:
  • Converts AC → DC
  • Charges battery
• Battery (12V) powers system during outages

Key technical characteristics

Type

• Step-down transformer
• Iron-core laminated type

Output type

• Usually AC output
• Converted to DC on control board (via rectifier)

Protection

• Often includes:
  • Thermal protection (internal or external)
• System also has:
  • Motor thermal overload protection

Mounting

• Internal (inside control box)
• Or panel-mounted

Real-world equivalent transformer

If you had to replace it, you’d be looking for:

A standard control transformer, e.g.:

• 230V → 24V AC
• 40VA–100VA
• Panel mount

 From industry norms:

• “230V to 24V transformer” is the most common spec for door systems

Failure symptoms

If the transformer fails, you’ll typically see:

•  No power to control panel
•  Push button doesn’t respond
•  No LEDs/display
•  Accessories dead (photocells, receivers)

But:

• Mains power may still be present at input

How to test it (quick field method)

With a multimeter:

1. Check primary:
   • ~220V AC present
2. Check secondary:
   • ~24V AC output

 If:

• Input OK
• Output = 0V
   Transformer is faulty

Key specs

•  Input: 220–380V AC
•  Output: ~24V AC (typical)
•  Power: 20–100VA
•  Function: Power control system
•  Location: Inside operator/control panel
•  Not a standalone branded product

(The Company reserves the right to amend product specifications and information without notice.)