2017 AEESOLAR DEALER CONF. Rapid Shutdown Requirements for NEC 2017 Presented by: Bill Brooks, CMP 4
2017 NEC Statistics for Article 690 Whole article was reduced from 11,000 words to about 8,000 words. Rapid shutdown increased from 133 words to over 1100 words. Dc loads, stand-alone systems (ac loads), and battery storage systems have historically been considered part of Article 690. With the advent of a whole new articles on energy storage systems [Article 706], stand-alone systems [Article 710], microgrids [new Part IV of Article 705], and dc microgrids [Article 712] all these sections were removed from 690.
PV system circuits installed on or in buildings shall include a rapid shutdown function to reduce shock hazard for emergency responders in accordance with 690.12(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 690.12
Several Significant Changes Proposed: 1. Greatly increased detail of rapid shutdown switch including location and signs 2. Define array zone within 1 of modules 3. All 3 options for reducing shock hazards within the array boundary. 1. Listed Rapid Shutdown PV Array 2. Curtail voltage of conductors within array zone to 80V 3. No exposed metal or conductors in PV array and array more than 8 from grounded metal. 4. Require equipment to be certified for rapid shutdown
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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
ROOFTOP JUNCTION BOX TO TRANSITION FROM TC-ER CABLE TO THWN-2 PV ARRAY 30 VOLTS OR LESS 80 VOLTS OR LESS ABOVE 80 VOLTS CONDUIT RUN OVER 10' LONG GARAGE EXISTING EXTERIOR SERVICE PANEL
Informational Note: One example of why an initiation device that complies with 690.12(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.
For AEE Internal Use Only. SOURCE CIRCUIT COMBINER W/ CONTACTOR WITHIN 10' OF ARRAY IF OUTSIDE, OR WITHIN 5' OF ENTERING THE ROOF, WHICHEVER IS SHORTER PV ARRAY 30 VOLTS OR LESS 80 VOLTS OR LESS ABOVE 80 VOLTS CONDUIT RUN OVER 10' LONG RAPID SHUTDOWN SWITCH GARAGE REMOTELY ACTIVATED DC SWITCH STANDBY LOAD CENTER INVERTER EXISTING EXTERIOR SERVICE PANEL BATTERY REMOTELY ACTIVATED AC SWITCH
Multiple PV systems on a single service Not more than 6 switches or circuit breakers or combination thereof in a single enclosure or a group of separate enclosures
Equipment that performs the rapid shutdown functions, other than initiation devices such as listed disconnect switches, circuit breakers, or control switches, shall be listed and labeled, and identified for providing rapid shutdown protection. Informational Note: Inverter input circuit conductors can remain energized for up to 5 minutes with inverters not listed for rapid shutdown.
A rapid shutdown switch shall have a label located on or no more than 1 meter (3 ft) from the switch that includes the following wording: RAPID SHUTDOWN SWITCH FOR SOLAR PV SYSTEM
1. String inverter located at the edge of the array with dc-to-dc converters or shutoff switching devices at each module. 2. Micro-inverters that segment each module (1-4 PV modules per inverter) 3. Building-Integrated PV array with no exposed metal or wiring and installed more than 8 from grounded metal.
Standard needs to be developed to certify equipment. Process is wrapping up that is focusing on products for the 2014 NEC and products outside of array boundary for the 2017 NEC As the existing standard process is established for products address outside array boundary, work is starting to develop certification process for listed rapid shutdown PV array products