Home Power Factor & Frequency Relays Monitored frequency range - 40 - 60 Hz Power Factor & Frequency Monitoring Relays - Monitored frequency range - 40 - 60 Hz Filters and sorting Cancel the filter Recommended Bestsellers Cheapest Most expensive -30% Quick info HRF-10 Hlídací relé frekvence On request £ 37.45 excl. VAT £ 53.50 Add to cart Share Tweet Pin It