Clear-Com PS-704 - Manual (Page 9)

P S - 7 0 4 F O U R - C H A N N E L P O W E R S U P P L Y
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• AUTOMATIC POWER RESTORE: The PS-704’s internal power
supply senses the difference between short-term and long-term shorts and
overload conditions. After the first few times a short or overload occurs,
the power supply will try to restore power after only 0.5 seconds. If the
short or overload persists or occurs repeatedly, the power supply will take
progressively longer (to a maximum of 20 seconds) to try to restore
power. This protects the power supply from damage due to overheating.
Once the short is removed, the channel will recover, even under a full load
condition. The automatic power restore times are shown in the following
chart:
Figure 1-1: Automatic Power Restore Times
• INDIVIDUAL CHANNEL SHORT CIRCUIT PROTECTION: Each
individual channel is separately overload and short circuit protected and
may draw as much as 1.2 amperes, though the total to both channels is
limited to 2 amperes. A short on any one intercom line will not bring the
whole system down.
• FRONT PANEL INDICATIONS: There are four overload indicators on
the front panel (one for each channel) and a power indicator for the power
supply. The overload indicators light steady when an overload or short
condition is detected. They blink if power to a channel has been shut off
as a result of an overload or short.
• PARALLELING MULTIPLE POWER SUPPLIES: Multiple power
supplies can be paralleled to increase system capacity. The PS-704’s
internal power supply will automatically detect the actions of other power
supplies during overloads and short circuits to restore power as quickly as
possible.
• MULTI-CHANNEL REMOTE STATIONS MAINTAIN THE
POWER LINE ISOLATION: The RM-704, RM-702 and KB-702 as
well as any two or four channel remote station or beltpacks are designed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
5
10
15
20
0
0
0.5
2
4
7
14
20
Number of
seconds to
restore
Number of recent shorts or overloads