3B
System Interfacing
CPI Canada Inc.
Page 3B-8
Rev. E Indico 100 Series Service Manual Ch # 740895-05
3B.3.3 Selecting Output Voltages (Cont)
The above voltage sources are not compatible with:
•
Collimator lamps (24 VDC 150 watts). These exceed the 4 Amp rating of the 24 VDC supply.
•
Fluorescent lamps. These have high starting currents and generate transients when the tube strikes.
•
Some inductive loads may cause difficulties (for example some motors, under table tube fans, and
solenoids).
IT IS STRONGLY RECOMMENDED THAT CLAMPING / RECOVERY DIODES BE USED ON INDUCTIVE
DEVICES SUCH AS RELAYS ETC WHICH ARE CONNECTED TO THE ROOM INTERFACE BOARD.
Voltage selections are made by adding jumper wires from TB11 to TB8, TB9, or TB10, and placing the
jumpers on JW1, JW2, JW3, JW4, or JW5 in the live contact position.
Review figure 3B-3 for typical examples.
1
2
3
4
5
K 2
K 1 K 4 K 3
K 6
FIL E: IN _R M JM P.CDR
Figure 3B-3: Typical jumper arrangement on the room interface board
SOME INSTALLATIONS REQUIRE THAT THE OUTPUTS OF RELAYS K1, K2, K3, K4, K6 OR K8 DRIVE
THE INPUTS OF OPTO COUPLERS. IN INSTALLATIONS WHERE THESE RELAYS SOURCE 110 OR 220
VAC, THE LEAKAGE CURRENT THROUGH THE R-C SNUBBER ACROSS THE RELAY CONTACTS MAY
BE SUFFICIENT TO ENERGIZE THE OPTO COUPLERS WHEN THE RELAYS ARE OPEN.
IF THIS IS EXPERIENCED, THE R-C SNUBBER SHOULD BE DISCONNECTED FROM THE
CIRCUIT. CUTTING AND REMOVING THE JUMPER WIRES PER THE TABLE ON THE NEXT PAGE WILL
DISABLE THE R-C SNUBBER CIRCUIT. THE JUMPER WIRES SHOULD BE CUT AS NEAR AS
POSSIBLE TO THE PADS ON THE BOARD, THEN AS MUCH AS IS POSSIBLE OF THE WIRE JUMPER
SHOULD BE REMOVED. THIS IS NECESSARY TO WITHSTAND THE OPEN CIRCUIT VOLTAGE
ACROSS THE RELAY CONTACTS.
