Data Sheet ( PDF )

Reason for Use:

The proper operation of electrical and electronic devises in general is based on the availability of a relatively steady line voltage.  This condition is usually met without special precaution when the several connected loads all consume a steady amount of power.  If one or more of the loads are of a varying or pulsating nature, then the degree of steadiness of the line voltage (i.e. line voltage regulation) will be dependent upon several factors – such as:

1. The voltage regulation of the power service to the installation (i.e. is the power service a firm-heavy source with adequate capacity or a soft source at the end of a rural line)
2. The size of the conductors between the power service and the connected load.  In many cases the size is not adequate for the load, thus causing a large voltage drop.
3. The size and voltage regulation of the standby generator.
4. The relative size of the pulsating load as related to the total connected load at site.

Also of prime importance is the relative sensitivity of the electronic or radio equipment to the variations in the line voltage.  The rules of the FCC and FAA require the 300mm Beacon to flash ON and OFF at a rate between 20 and 40 flashes per minute.  The beacon normally uses two 620 watt lamps, thus a pulsating load of 1240 watts.  Assuming a rate of 30 FPM, the 1240 watt load is ON for 1-1/3 seconds and OFF for 2/3 seconds.  Due to some inrush current when the lamps are ON, the effect on the line voltage may be slightly more severe than flashing a resistive load of 1240 watts. In some installations, the 1240 watt pulsating load may represent a substantial portion of the total connected load.  In these cases the variations in the line voltage may be quite severe and some corrective means must be considered. Fortunately, a relatively simple and quite effective corrective means is available – a Load Balance Resistor.  This consists of a 1200 watt resistive load which is switched ON as the Beacon load is switched OFF and vice versa.

The Hughey and Phillips LB112120 and LB212480 Load Balance Resistors (LBR) are designed for use with flashing Beacons and will minimize fluctuations in the beacon lighting load circuit, when used is conjunction with our 9LC Lighting Controls.  Housed in a louvered galvanized steel case, the LBR is suitable for outdoor installations.  The mounting brackets are movable in order to provide for mounting against a vertical or horizontal surface.  Connection to the LBR is made to a terminal strip mounted in a watertight cast junction box which is tapped for ½” conduit or conduit fitting.  The resistive elements are of the strip type to provide uniform heat distribution and are of steel-sheath construction with compressed insulation.