HiQ System Features
NEC Rapid Shutdown 690.12 - A Natural Fit
If your inverter is designed to hang on a wall, it's hard to force-fit it onto a roof, with the poor thing forced to lie almost on it's back. It's a lot easier if your inverter was designed from the ground up to be array-mounted, like the HiQ TrueString inverter. Tuck it out of the way, safe in the knowledge that it's easily within the 10 foot and even the 1 foot area specified in the NEC.
Cradle Compromises or Purpose-Designed Solution?
The HiQ Solar TrueString inverters were designed from the outset to be array-mounted. Below is a quick comparison of our approach with the large 3-phase string inverters that are increasingly common.
|3-phase String on a Cradle||HiQ TrueString Mounted Under the Array|
|1.||Satisfies 2014 NEC 690.12 Rapid Shutdown 10’ rule?||When installed correctly and within 10 feet of the array, yes||When installed correctly and within 10 feet of the array, yes|
|2.||Satisfies 2017 NEC 690.12 Rapid Shutdown 1’ rule?||Possible, but awkward - not designed for this||When installed correctly and within 1 foot of the array, yes|
|3.||Ease of designing with||Requires extra wide walkways or takes up space in mandated walkways||Sits under the array, but easy to access unlike micro inverters|
|4.||Ease of installation||Typically weigh more than 150 lb., hard to lift, requires more than one person. Requires extra effort and cost to buy and assemble the cradle||Weighs 24 lb. Easy to lift, easy to install, easy to carry spares.,Easy to install by one person.,Connector-based electrical connections.|
|5.||Reliability||LCDs, fans etc. require maintenance and regular replacement. Often these inverters use electrolytic capacitors. Sits in full sun. Not being used as originally intended||NEMA6, no electrolytics, no display, no fans. Maintenance-free. Robust, single circuit board, automotive grade components. Being used as intended|
|6.||Ease of replacement later||150 lb.+, hard to get replacement units onto a roof later, requires several people in the crew to do so||Tuck one under your arm, climb a ladder. Unclick the connectors, click in the new one. Easy|
|7.||Other||Usually strings are paralleled, making poor granularity of monitoring, fault-finding and arc detection||Each string has separate MPPT, monitoring. Single string arc detection, placed next to the modules, makes arc detection reliability better, and reduces occurrence of false-positives|