Miranda NV5100MC Master Control, Reference Manual

Page: 42 / 240

28 Rev 2.10 • 17 Feb 11
3. Frames
Connectors
Figure 3-7 shows suggested alarm circuit implementations. You can use signalling devices other
than LEDs or in addition to LEDs. For example, you can operate a buzzer or other audible alarm to
warn operators of a potential problem.
Figure 3 -7. P ower Supply Alarms
CAUTION: The voltage of the external power supply for alarm signalling should not exceed
±30VDC. Resistors should be sized to limit the current through each internal alarm contact to less
than 150mA.
If the load is inductive, the alarm contacts should be protected with a parallel, reverse-biased diode.
Power
The frame has two power supply bays (and two power connectors) to support redundancy. Only one
power supply is actually required.
Connectors
At the middle right portion of the rear of the frame are 2 AC connectors:
The frame has one (IEC) 3-conductor power connection for each of its 2 power supplies. These
should be connected to a 90–130VAC or 180–250VAC 15A grounded circuit wired in accordance
with local electrical codes.
Fuses for both AC power inputs are located on their respective power supplies. Ensure that the fuse
ratings comply with specific requirements in your area. A 7.5A fuse is required for 110/120VAC
applications. For 220/240VAC operation, a 3.75A fuse is required.
1 2
1 2
COM
COM
Customer’s Power
30VDC max, 150mA max
Customer-supplied relay contacts
closed during normal operation,
open during alarm
Normally on, the lamp turns off
to indicate failure.
Normally off, the LEDs
turn on to indicate failure
Customer’s Power
30VDC max, 150mA max
Customer’s Ground
Customer’s Ground
Current flows between contacts
during Internal alarm condition
Current flows between contacts
during Internal alarm condition