Philippine Electrical Code 2017 Edition - Requirements
Effective January 1, 2019, the Philippine Electrical Code 2017 Edition, requires PV systems to be provided with a rapid shutdown for the safety of emergency responders. Rapid shutdown devices dramatically reduce the potentially dangerous residual energy often found in string inverter PV systems. This will prevent electrocution of firefighters and other first responders safe in the event of a fire in the building.
Rapid Shutdown of PV Systems on Buildings
6.90.2.6 Rapid Shutdown of PV Systems on Buildings. PV system circuits installed on or in buildings shall include a rapid shutdown function to reduce shock hazards for emergency responders in accordance with 6.90.2.6(A) through (D).
Exception: Ground-mounted PV system circuits that enter buildings, of which the sole purpose is to house PV system equipment, shall not be required to comply with 6.90.2.6.
(A) Controlled Conductors. Requirements for controlled conductors shall apply to PV circuits supplied by the PV system.
(B) Controlled Limits. The use of the term array boundary in this section is defined as 305 mm from the array in all directions. Controlled conductors outside the array boundary shall comply with 6.90.2.6(B)(1) and inside the array boundary shall comply with 6.90.2.6(B)(2).
(2) Inside the Array Boundary. The PV system shall comply with one of the following:
FPN: A listed or field labeled rapid shutdown PV array is evaluated as an assembly or system as defined in the installation instructions to reduce but not eliminate the risk of electric shock hazard within a damaged PV array during fire-fighting procedures. These rapid shutdown PV arrays are designed to reduce shock hazards by methods such as limiting access to energized components, reducing the voltage difference between energized components, limiting the electric current that might flow in an electrical circuit involving personnel with increased resistance of the conductive circuit, or by a combination of such methods.
(2) Controlled conductors located inside the boundary or not more than 1000 mm from the point of penetration of the surface of the building shall be limited to not more than 80 volts within 30 seconds of rapid shutdown initiation. The voltage shall be measured between any two conductors and between any conductor and ground.
(3) PV arrays with no exposed wiring methods, no exposed conductive parts, and installed more than 2500 mm from exposed grounded conductive parts or ground shall not be required to comply with 690.12(B)(2).
The requirement of 6.90.2.6(B)(2) shall become effective on January 1, 2019.
(C) Initiation Device. The initiation device(s) shall initiate the rapid shutdown function of the PV system. The device “off” position shall indicate that the rapid shutdown function has been initiated for all PV systems connected to that device. For one-family and two-family dwellings, an initiation device(s) shall be located at a readily accessible location outside the building.
The rapid shutdown initiation device(s) shall consist of at least one of the following:
(1) Service disconnecting means
(2) PV system disconnecting means
(3) Readily accessible switch that plainly indicates whether it is in the “off” or “on” position
Informational Note: One example of why an initiation device that complies with 6.90.2.6(C)(3) would be used is where a PV system is connected to an optional standby system that remains energized upon loss of utility voltage.
Where multiple PV systems are installed with rapid shutdown functions on a single service, the initiation device(s) shall consist of not more than six switches or six sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, or in a group of separate enclosures. These initiation device(s) shall initiate the rapid shutdown of all PV systems with rapid shutdown functions on that service. Where auxiliary initiation devices are installed, these auxiliary devices shall control all PV systems with rapid shutdown functions on that service.
(D) Equipment. Equipment that performs the rapid shutdown functions, other than initiation devices such as listed disconnect switches, circuit breakers, or control switches, shall be listed for providing rapid shutdown protection.
FPN: Inverter input circuit conductors often remain energized for up to 5 minutes with inverters not listed for rapid shutdown.
Typical Connection Diagram
