NEC Article 408.30(A)"Where an overcurrent protective device is accessible to other than qualified persons and where the voltage between conductors exceeds 250 volts, means shall be provided to lock or tag such overcurrent protective device in the open position."NEC Article 705.12(E)"Where main disconnects are installed in buildings for connection to distribution systems having a nominal voltage greater than 250 volts, the main disconnect shall be suitable for use as service equipment and shall be provided with a marking of the maximum size of the disconnect that shall be installed in the building."Analysis

The question is whether the landlord's 3000A service breaker, which is located 200 feet away from the main distribution panel (MDP), can serve as the main disconnect for the MDP.1.

Overcurrent Protection

The landlord's 3000A service breaker meets the requirement of Article 408.30(A) for an accessible overcurrent protective device. It is accessible to other than qualified persons and the voltage between conductors exceeds 250 volts.
2.

Main Disconnect

The landlord's 3000A service breaker is installed near the service entrance and is suitable for use as service equipment, meeting the requirements of Article 705.12(E).
3.

Remote Control

Article 408.30(A) does not require a disconnect means for the MDP if the incoming service breaker can be locked out. In this case, the landlord's 3000A service breaker has a lock-out mechanism, which allows it to be safely locked in the open position.

Conclusion

Based on the analysis of the NEC, it is

permissible to use the landlord's 3000A service breaker as the main disconnect for the MDP, provided that it is locked in the open position when servicing the MDP. This is because the service breaker meets the requirements for overcurrent protection and a main disconnect, and it can be locked out remotely to prevent accidental energization. Flag for review