165A Low Voltage Pole Mounted Circuit Breaker Adapted To Significant Load Imbalances

1-Post circuit breaker with digital trip unit Description
Circuit breaker unit
These units (4 poles 3 of which are protected) cut off in air with metal partition chambers to break the arc.
When the circuit breaker is open, a contact makes an electrical link between the transformer neutral and the station structural earth.When the circuit breaker is closed, a spark gap limits the rise in potential of the LV neutral, in relati.n to the structural earthing, for a value exceeding 10 kV.
The circuit breaker is installed inside a weatherproof GRP case.
2 - Digital trip unit Trip time as per HN 63-S-11 + corrected values (in bold type) to match the selectivity of the TPC fuses.
Digital Trip Unit
The Digital Trip Unit protects the three ratings of the post-mounted transformer (50 kVA, 100 kVA and 160 kVA) , whether it be a conventional transformer (no internal protection) or a new transformer with protection (TPC).
The transformer protection rating is set by a selector.
The micro-controller assesses the transformer temperature in real time, based on the currents in the three phases and the external ambient temperature. This ambient temperature is computed based on the probe and a mathematical model that is also a function of the three phase currents.

Working Ambient

Note: No fire, no explosion hazards, no chemical c.rrosion and recurrent severe vibration.

1.lncoming wiring clamp

2.lncoming wiring hole
3.Arc chute grid
4.Operation mechanism
5.Digital trip unit
6.Load indicator trip indication
7.Position indicator
8.Operation handle

1.Incoming wiring clamp
Users can connect the transformer1s low-voltage side or other four-phase (3P+N) power sources as the incoming power supply for this circuit breaker. Additionally, its unique design eliminates the need for users to crimp lugs before connection (as shown on figure 2).
Additionally, the wiring clamps below it serve as outgoing and phase sequence must be ensured during connection.
2. Incoming wiring hole
Users can insert cables into the circuit breaker at this location. Similar to point 1, its lower section is designed for outgoing connections.
3. Arc chute grid
This grid is designed to extinguish arcs during circuit breaker operation. Users can replace this component based on the current condition of the grid.
4. Operation mechanism
This area houses the circuit breaker's operating mechanism. Designed as a spring-charged closing mechanism with a trip-free release, it can be operated via a floor-mounted handle.
5. Digital trip unit
Digital Trip Unit, distinct from traditional thermal trip units or fixed-function PCB hardware trip units, features embedded current transformers with phase-toneutral voltage supply. It complies with the trip response time and accumulated overload response time specified in the HN63-S11 standard. The capacity is configurable to 50, 100, or 160 kVA as required.
6. Load indicator trip indication
The orange component will drop down when the accumulated load time is reached (indicated by Component 6 rotating clockwise past the O position) and Component 10 is in the configuration shown. This action will internally trigger the circuit breaker to trip.
7. Position indicator
The green component protrudes minimally at the bottom when in the closed position.When in the open position, a significantly longer section becomes visible.
8. Operation handle
This handle connects to the floor-mounted operating handle. During installation,users must secure the linkage pin with a split pin. Downward movement initiates tripping/spring-charging, while upward movement performs the closing operation.
9.Load trip enable/disable handle
This handle enables or disables the trip function of the load indicator.
Downward position:
Operate the 9# Operation Handle downward to charge the mechanism, then upward to cl.se the circuit breaker. During this motion, the 7# Load lndicator Trip Indication resets. If the circuit breaker detects overload, the 6# Load Indicator activates When its pointer rotates clockwise past the O position, the breaker trips.
Inward position:
The load indicator continues monitoring but disables tripping.

Figure 4 shows the installation diagram. The floormounted operating handle connects to the circuit
breaker via a standard iron pipe. The illustrated utility pole is circular; if a square utility pole is used,
this must be specified in the installation notes.