Specifications

M GD-100 M anual

6109-9000 Rev 3 35

CAUTION: Before you carry out the bump test or calibration:

• Advise occupants, plant operators, and supervisors.

• Check if the MGD-100 is connected to external systems

such as sprinkler systems, plant s hut down, external

sirens and beacons, ventilation, etc. and disconnect as

instructed by the customer.

• For one-alarm systems you should deacti vat e the 3-min

alarm delay (if selected) by moving jum per JP1 to the

“off” position.

• Ideally, for bump t est or calibration the MGD-100 should

be powered up overnight. See Section 5 for more

information.

6.2. Electrical Reset of One-Alarm Systems

Reset, if necessary, the Standby and Alarm Threshold Voltage to the

factory settings as shown on the calibration label. Electrical res et

information is listed on the label on the side of the enclosure and is

unique to that sensor. Two adj ustments are required and they are

performed on the MGD-100 controller unit.

NOT E: If the sensor standby voltage (SSV) is greater than

the alarm threshold voltage, as in when a gas leak occurs,

then an alarm condition occurs (red LED, siren, relay

operates).

If the SSV falls below 0.18 V, a fault condition will be shown

on the controller (red LED, no siren, relay does not operate).

Tools required:

• A voltmeter (crocodile clips recommended)

• Factory set point electric values (as shown on the rating label)

• Screwdri ver (depending on enclosure).

Step Electrical Re set of One-Alarm Systems

First disable the 3-minute alarm delay by movi ng the jumper

link at JP1 to the “OFF” position. See Figure 13 and Fi gure

15.