Operation; Continuity Testing - Cleveland Controls 6650 Instruction Manual

2.0 OPERATION

2.1 CONTINUITY TESTING

2.1.1 Prove circuit integrity, check and calibrate sensing switches
using the continuity testing capability of the Digital
Manometer. Note: When testing an installed switch,
first disconnect the power source from the switch
to avoid shock hazard and damage to the continuity
tester.
2.1.2 The continuity circuit consists of two LED's and a series
resistor in open circuit condition. Continuity between
COMMON (C) and either Normally Open (NO) or Normally
Closed (NC) illuminates the red (NO) or green (NC) LED.
2.1.3 A non-resistive ⅛ amp fuse is located in the power supply
connection to protect the battery and manometer circuits
if the continuity circuit is inadvertently connected to AC
power or any other high potential source.
2.1.4 To determine the pressure at which a sensing switch opens
or closes, connect the continuity test cable to the three
continuity jacks on the front panel of the manometer (see
Section 1.6, above).
2.1.5 Connect the color-coded wires of the test cable to the
sensing switch contacts. Be sure to connect the common
wire (C) to the common contact, the normally open (NO)
wire to the normally open contact, and the normally closed
(NC) wire to the normally closed contact.
2.1.6 Connect the manometer's pressure inputs in parallel
with the switch. Press the manometer's ON/OFF switch
to the ON position, and push the 0-10 In. H2O unit of
measurement switch. When the display appears, adjust
the ZERO control until it reads "0.00."
2.1.7 At pressures below the sensing switch set point, the green
LED (NC) will be on, indicating that this circuit is closed.
The red LED (NO) will remain off.
2.1.8 At the switch's set point, as indicated on the manometer,
the green NC LED will go out and the red NO LED will
come on.
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Instruction Manual DM-6650.02