Alpha Technologies Node Power Supply - Manual (Page 25)

ONLY qualifi ed personal should connect the utility power. Power must be connected in
compliance with local electrical codes, and common safety practices must be observed.
WARNING!
2.5 Connecting the Utility Power
• Connection to utility power must be approved by the local utility before installing the power supply.
• UL and NEC require that a service disconnect switch (UL listed) be provided by the installer and be
connected between the power source and the Alpha power supply.
• Connection to the power supply must include an appropriate service entrance weather head.
ATTENTION:
Utility power enters the enclosure through an .875" knockout on the side or rear of the NPS. The enclosure
accepts a standard electrical fitting.
A “high-magnetic” trip circuit breaker must be used in order to accommodate the high-inrush currents normally
associated with the start-up of ferroresonant transformers (400A, no-trip, first-half cycle). Do not replace
this circuit breaker with a conventional service entrance circuit breaker. Alpha recommends Square D circuit
breakers for 120V installations, and HACR (heating and air-conditioning) breakers for 240V installations.
Alpha Technologies offers a high-magnetic Square D circuit breaker and a BBX option (a UL Listed service
entrance). Contact your local sales representative for more information.
Description Alpha Part Number Square D Part Number
240V Installation — HACR (15A) 470-224-10 QO215
120V Installation — High-Magnetic (20A) 470-017-10 QO120HM
120V Installation — High-Magnetic (15A) 470-013-10 QO115HM
BBX — External Service Disconnect 020-085-10 QO2-4L70RB
BBX — External Service Disconnect 020-141-10 QO8-16L100RB
Table 2-1, Service Entrance Circuit Breaker Requirements
Alpha recommends 12AWG wiring to accommodate a 90V power supply.
NOTE:
25 031-295-B0-001 Rev.A
2.0 Installation