Socket & See SOK65/16HD 400V Industrial Socket Tester
400V 5 Pin Industrial Socket Tester with Phase Sequence Indication
The Socket & See SOK65/16HD 400V Industrial Socket Tester provides a quick and straightforward way to check 400V 5-pin industrial socket outlets for phase presence, phase sequence and protective earth condition.
Simply insert the tester into the socket and switch on the supply. Individual LEDs indicate whether each phase is present or disconnected. When all three phases are connected, the LEDs provide an immediate indication of the phase sequence.
A correct clockwise phase sequence is shown by three rotating green LEDs accompanied by a continuous audible tone. An incorrect counter-clockwise sequence is indicated by three rotating red LEDs together with a warbling warning tone, helping the user distinguish the condition quickly and clearly.
If a phase is missing, its corresponding LED remains off while the other two phase LEDs flash to confirm that they are present. A fourth LED, identified as PC-N, indicates the presence or absence of the protective earth conductor when all three phases are present: green indicates presence and red indicates absence.
For testing 32A industrial sockets, the Socket & See SOK65 can also be used with the optional SOK ADP65 adaptor.
Order the Socket & See SOK65/16HD today – a robust 400V 5-pin industrial socket tester providing fast phase presence, phase sequence and protective earth indication.
Socket & See SOK65/16HD Key Features:
- Designed for 400V 5-pin industrial socket testing
- Clearly identifies phases L1, L2 and L3
- Provides instant phase sequence indication
- Three rotating green LEDs indicate correct clockwise sequence
- Three rotating red LEDs indicate incorrect counter-clockwise sequence
- Continuous audible tone indicates correct sequence
- Warbling warning tone indicates incorrect sequence
- Clearly indicates when an individual phase is missing
- PC-N LED indicates protective earth presence or absence
- Tough rubber holster for heavy-duty use
- Secure push-fit connection
- Hard-wearing flexible cable
- Long-life LED indicators
- Compatible with SOK ADP65 for testing 32A industrial sockets
▶ Industrial Socket Tester Range – Full Line-Up, Features & Demonstration:

Please note this video does not cover the full range.
Why Choose the Socket & See SOK65/16HD?
The Socket & See SOK65/16HD makes checking 400V 5-pin industrial socket outlets quick and easy to interpret.
Its combination of colour-coded LEDs and audible tones allows the user to immediately identify correct or incorrect phase sequence. Individual phase indication also makes it straightforward to identify when a phase is missing.
The additional protective earth indication provides further useful information about the socket condition, while the tough rubber holster, hard-wearing flexible cable and long-life LEDs make this 400V industrial socket tester suitable for regular professional use.
For greater flexibility, adding the optional SOK ADP65 allows the compatible 16A tester to be used when testing 32A 400V 5-pin industrial sockets.
Specifications:
| Features | |
| Voltage | 400V |
| Socket Configuration | 5 Pin |
| Phase Identification | L1 / L2 / L3 |
| Phase Presence Indication | LED |
| Correct Phase Sequence | Green LEDs Rotating Clockwise |
| Incorrect Phase Sequence | Red LEDs Rotating Counter-Clockwise |
| Correct Audible Indication | Continuous Tone |
| Incorrect Audible Indication | Warbling Tone |
| Missing Phase Indication | ✓ |
| Protective Earth Indication | Green / Red PC-N LED |
| Housing | Tough Rubber Holster |
| Connection | Secure Push Fit |
| Cable | Hard-Wearing Flexible Cable |
| Indicators | Long-Life LEDs |
| 32A Socket Testing | With optional SOK ADP65 adaptor |
❓ Frequently Asked Questions (FAQ)
Q1: What is the Socket & See SOK65/16HD used for?
A. The Socket & See SOK65/16HD is designed for checking 400V 5-pin industrial socket outlets, including phase presence, phase sequence and protective earth condition.
Q2: How does the SOK65 show a correct phase sequence?
A. A correct clockwise phase sequence is shown by three rotating green LEDs together with a continuous audible tone.
Q3: How does the SOK65 indicate an incorrect phase sequence?
A. An incorrect counter-clockwise phase sequence is shown by three rotating red LEDs accompanied by a warbling warning tone.
Q4: Can the SOK65 identify a missing phase?
A. Yes. If a phase is missing, its corresponding LED remains off while the other two phase LEDs flash to indicate that they are present.
Q5: Does the SOK65 indicate protective earth condition?
A. Yes. When all three phases are present, the PC-N LED indicates the protective earth conductor condition. Green indicates presence and red indicates absence.
Q6: Can the Socket & See SOK65 test 32A industrial sockets?
A. Yes. The Socket & See SOK65 can be used with the optional SOK ADP65 adaptor for testing 32A industrial sockets.