Vigilant MICROVAC, Owner'S Manual

Page: 21 / 36

Document: LT0109 Vigilant MICROVAC Owner's Manual
Installation, Wiring, Setup, and Commissioning
Issue 1.31 5 April 2000 Page 2-9
──────────────────────┐ To Speakers
┌ J47 ██ ├────────────────────────────────────────────────────────┬───── >
Speakers
─┤ │ │
│ J46 ██ ├────────────────────────────────────────────────────────┼───┬─ >
└ │ + │ │
┌ J45 ██ ├── ┌─────────┐ ───┴───│
Transformer
─┤ │ │ ┌┴┐ 2200uF ──┬───│
Secondary
│ J44 ██ ├── │ 5k6 │ │ 63V - │ │
└ │ │ └┬┘ ┌──────────────────────┐ │ │
┌ J43 ██ ├─────────┘ ├──┐ │ │ │ │
Transformer
─┤ │ ┌┴┐ │ │ │ │ │
Primary
│ J42 ██ ├─────────┐ 560 Ω│ │ └────────┤ A Booster 1 00V ├─┘ │
└ │ │ └┬┘ │ INPUT Amplifier OUT │ │
┌ J4 1 ██ │ │ ├───────────┤ B ├─────┘
Low Level
─┤ │ │ ┌┴┐ │ │
Out
│ J40 ██ │ │ 5k6 │ │ - - - - │ 0V │
└ │ │ └┬┘ Shield └──────────────────────┘
│ │ │
Microvac Main PCB
│ └─────────┘
│
│
│
──────────────────────┘
FIGURE 2.11
This will provide line monitoring for short and open circuits on the speaker line and amplifier
monitoring for faults in the Microvac or booster amplifier.
The steps for commissioning a Microvac with a third party booster amplifier are as follows -.
(a) Adjust the volume controls on the Microvac and Booster Amplifier to approximately mid
position.
(b) Power up the Microvac and Booster amplifier. The Microvac will show a line fault ('L' on
the 7 segment display) approximately 40 seconds after power up. You should be able
to reset it using the MUTE button on the PCB after approximately 3 minutes. This is
the time it takes for the large capacitor on the Booster output to charge up. (This time
will also apply for recovery from a speaker line fault.) During the time the Microvac is
announcing the line fault it will not produce any tones, as it thinks the line is short
circuited.
(c) If the Microvac is announcing an amplifier fault ('A') on the 7 segment display, increase
the setting of the volume control on the Booster amplifier to well past the point where
the Microvac goes out of fault. This will increase the level of the 28kHz monitoring
tone.
(d) Select the Evacuate tone on the Microvac and adjust the level control on the Microvac
to get suitable sound levels. If the resulting voltage is much less than 100V, then the
speaker transformer taps should be set to a lower wattage, and the level control re-
adjusted.