Avionics Bending: AC Frequency and Volts Indicators

L-1011 AC Frequency and Volts Meter

The L-1011 Electrical Panel has two instruments that show the AC Frequency and AC Volts measured on a specific subsystem. The image above shows the frequency (left) and AC volts (right) measured directly from the 400Hz Inverter. The instrument on the left indicates 400Hz and the one on the right indicates 115V AC.

Both instruments on the L-1011 had been made by The Lewis Engineering Company which was later acquired by BFGoodrich and closed down in 2000 as a result of the merger. Here is the pinout information for these instruments:

Frequency Meter 152LCF5B

Pin      Function
1        5V AC Lighting (H)
2        5V AC Lighting (L)
3        Chassis Ground
4        115V 400Hz (H)
5        115V 400Hz (L)

AC Volts 152LCV8

Pin      Function
1        5V AC Lighting (H)
2        5V AC Lighting (L)
3        Chassis Ground
4        PMG DC Input
5        115V 400Hz (H)
6        115V 400Hz (L)