Bosch Power Tools DS240 Power Outage, Remote Indicator Plate Connector, Sensitivity Must not

To check the reference voltage, remove the receiver's access door and measure the reference voltage, using the supplied test cable, or measure the voltage at the DIS240 Remote Indicator Plate (if used). If the voltage is less than 3.8 VDC, remove the cover and perform a fine tune alignment including use of the Set-up switch. If above 4.2 VDC, press the Set-up button. Calibration is not necessary if the voltage is between 3.8 VDC and 4.2 VDC.

8.4 Power Outage

When power is removed, then reapplied to the receiver (such as in a power outage or alarm reset), the original reference voltage information is lost.

If the cover is on at the time of power-up, the receiver will automatically restart the internal set-up process (to get a new reference voltage) when power is applied. If the cover is off, the Set-up button will have to be pressed after the cover is reattached.

4.0
3.5
3.0
2.5
2.0
1.5
1.0					UL Minimum Sensitivity
0.5		30% 40%	50%	60%	70%
	20%
0.0	UL Maximum Sensitivity
30 (9m)		80 (24m)	130 (40m)		180 (56m)	230 (70m)	280 (85m)	330 (100m)

Distance Between Transmitter and Receiver

8.5 Remote Indicator Plate Connector

Momentarily connecting the orange and black leads of the connector (see Figure 16) will produce a test alarm. For a remote test, install a momentary switch between the orange and black wires.

ORANGE - Remote Alarm Test

BLUE - Analog ref. voltage out

BLACK - Common (-)

RED - Red LED indicator

YELLOW - Yellow LED indicator

GREEN - Green LED indicator

Figure 16 - Remote Indicator Plate Connector

The black and blue wires may be connected to an analog meter for reference voltage measurements. The red, yellow, and green wires may be connected to remote LEDs.

Each wire is current limited to a maximum of 10.0 mA DC.

8.6 Smoke Density/Obscuration Information

The total obscuration of the infrared beam is dependent upon the density and width of the smoke cloud along the beam path. As the width of the smoke cloud increases along the beam path, less dense smoke will be needed for an equal obscuration of the beam path. In practice, the smoke cloud is assumed to be the entire distance of the beam path; therefore, the total obscuration required for alarm should be selected by setting the Sensitivity Pot Setting as recommended in Section 7.2 Sensitivity Adjustment on page 5.

Since the total obscuration of the beam by smoke increases with distance between the units (because more smoke will be within the beam path), the detector can be made less sensitive as the distance increases. Additionally, the sensitivity of the detector should be made less at greater distances because obscuration by other contaminants such as dust increases. The sensitivity should be set to respond to the proper smoke obscuration and also to reduce the chance of a false activation.

As shown in Figure 17, if the expected smoke density is 0.5 percent per ft (per 30 cm), the obscuration at 50 ft (15 m) is 20 percent and at 250 ft (95 m) it is 73 percent.

Figure 17 - Smoke Density/Obscuration Chart

The next chart (Figure 18) shows the Sensitivity Pot Setting (total obscuration) that is needed for alarm.

Sensitivity	Total
Pot	Obscuration
Setting	at Alarm
2	20%
0 or 3	30%
4	40%
5	50%
1 or 6	60%
7	70%

Figure 18 - Sensitivity Pot/Obscuration Chart

8.7 Field Sensitivity Measurements

The detectors automatically compensate for the effects of dust or dirt accumulation on the covers and for component aging. The NFPA requires that the detector's sensitivity be measured in the field, and requires that these measurements be made within one year after initial installation and every alternate year thereafter (reference NFPA 72). A TK240 Test Kit should be ordered to test the unit’s sensitivity in the field. The chart (Figure 19) below represents alarm information for the filters in the TK240 as well as the Sensitivity Test Kit provided with the units.

Sensitivity	Must NOT		MUST
Setting		Alarm	Alarm
2	0%	(no filter)	40% filter
0 or 3	0%	(no filter)	60% filter
4	20% filter		60% filter
5	20% filter		80% filter
1 or 6	40% filter		80% filter
7	40% filter		80% filter

Figure 19 - Sensitivity/Response Chart

DS240/DS241 Installation Instructions © 2004 Bosch P/N: 22066P Page 7