ASD-120 SEQUENCED POWER DISTRO
5
destructive “pop” reaching the speakers. And in any large system whose compo-
nents present a large inrush load to the AC line (including electric motors, power
supplies, and power amplifiers of all kinds), sequenced powering can avoid exces-
sive inrush currents that cause circuit breakers to trip even though the steady-state
currents are not excessive.
The ASD-120’s front panel provides a three-position ON/SEQ/OFF switch
for each circuit that allows each circuit to be part of the power up/down sequence,
or to remain on or off independent from the sequence. An LED adjacent to the
ON/SEQ/OFF switch indicates when either the power-up or power-down sequence
is in progress. The sequence can be initiated with either momentary or maintained
switches, locally or remotely. A duplex outlet is provided for each delay step. A
locking switch with a removable key is provided for maximum security.
The sequence can also be controlled by input terminals on the rear panel,
so one or more ASD-120’s may be installed in remote locations and operated
via low-voltage control wiring. As the ASD-120 sequences on, it turns on high power
relays that allow power to flow to the rear panel outlets, and, in the same sequence,
it turns on low level relays that provide contact closures (or openings) that can be
used to control Furman PowerPorts, MiniPorts, PowerLinks, PS-PRO and PS-8R
Power Sequencers, or any other circuits that need to know when their particular
time delay has elapsed. Using one or more ASD-120’s can provide the capability of
controlling power and power sequencing for an entire system. Detailed information
is provided in the Remote Control section of this manual.
The ASD-120 has no line cord or master breaker, and is designed to be perma-
nently wired to a single phase 120/240V source with 60 amps per side capacity, or
to a three phase 120V source with at least 40 amps per phase capacity.
The ASD-120's design incorporates four busses, allowing wiring for 120/240V
single phase, or 208V three phase power. A strain relief clamp is provided that can
accommodate a cable or wire bundle up to 1.5 inches in diameter. Cable termina-
tion is a simple process of breaking out and stripping the individual conductors and
connecting them with set screws, and then tightening the strain relief clamp.
The user-supplied mains supply wiring connects to an internal buss assembly.
As shipped, the unit is configured for 3-phase power. Outlets A and D are supplied
by the X phase input, outlets B and E are supplied by the Y phase input, and outlets
C and F are supplied by the Z phase input. 120/240V input can be accommodated
by connecting outlets A, C, and E to X, and B, D, and F to Y. The Z input is not used.
Fast-on connections to the power input buss allow easy reconfiguration.
Please read the Wiring Instructions section of this manual to guide you through
the process of selecting and terminating the supply cable.
Wiring Instructions
Prior to use, the ASD-120 must be fitted with a proper supply cable, which must
then be connected to an adequate power source and disconnect. The following
instructions will guide you through the selection and connection process. All steps
should be done while the unit is disconnected from power and is not mounted in a
rack. Begin by removing the four screws that hold the top cover in place and put the
screws and cover aside.
1. Determine the power source. In North America, there are generally two
