Jands FP12, Руководство по эксплуатации

Страница: 12 / 20

Fault Diagnosis 5-1
Revision 0.1 – 3 June 1999 FP12 DIMMER USER MANUAL
5.0 Fault Diagnosis
NOTE
Contact your authorised JANDS Distributor for repairs or servicing.
In Australia refer all repairs to an authorised JANDS service agent or return the
faulty unit in suitable packaging to:
JANDS ELECTRONICS Service Dept,
40 Kent Rd
Mascot NSW 2020
Australia
5.1 Output protection
Each of the twelve output circuits is protected by a 10 amp fast-acting thermal/magnetic
circuit breaker. These breakers are designed to pass the rated current, but will disconnect
the output circuit for any overload condition (the larger the overload, the quicker the
disconnection).
NOTE: 3-pin GPO outlet sockets are rated at 10 amps. Dimmer channels should
not be loaded beyond the socket capacity.
The breakers protect the dimmer’s output devices from short-circuit loads and faulty
wiring looms, and save on expensive dimmer repairs. A tripped circuit breaker indicates a
load fault that requires immediate attention.
If a short-circuit lamp or output cable is plugged into the dimmer, the breaker will trip to
disconnect the fault from the dimmer. In nearly all circumstances, this is quick enough to
prevent damage to the output devices.
In some circumstances however, a triac failure may be experienced, although these
devices are usually quite reliable and robust. If a triac does fail, it will either turn a
channel on to full (triac short-circuit), or turn it off (triac open-circuit). If a triac fault
should occur, that channel may be isolated by tripping that channel’s circuit breaker.
These breakers have been specified for electrical protection, reliability and safety. They
will allow repeated turn-on surges to cold lamps without failure, while still protecting the
triacs. The breakers will interrupt large short-circuit fault currents without damage.
5.2 DMX faults
The FP12 dimmer features an “Output Hold” facility that “remembers” the last received
DMX message. In the event of a cable being unplugged or severed, the FP12 dimmer
rack will continue to output the “Held” DMX levels until a new DMX message is
provided.
The DMX IN LED will “flash” slowly if the DMX signal is removed.
Note that control consoles, when powered down, may transmit spurious DMX data
which can unintentionally cause dimmer channels to turn on. Disconnect mains power
when not in use.
The DMX receiver input is protected against extreme over-voltages across any input pins
and from any input to chassis. The “terminating” resistor is not protected against over-
voltages.