Amprobe ACD-14-PLUS Clamp-On-Multimeters Uživatelský manuál stáhnout pdf (Strana 11)

Measuring μA Current - See Figure 9

1. Set the Function Switch to and press the SELECT button for AC or DC is displayed.

2. Connect the test leads: Red to +, Black to COM.

3. Turn OFF power to the circuit being measured and break the circuit for connecting

test leads.

4. Turn ON the circuit and read the display.

μA Current function

Application notes:

The DCμA function is designed especially for HVAC/R ame sensor applications. The

0.1μA resolution is useful for identifying the minute current changes in ame detector

applications. Flame signal current check should indicate steady ame signal of at least

2μA for a rectication type, or 1.5μA for an ultraviolet type (8μA for self checking

systems). If a ame signal current with inadequate strength or uctuation beyond 10%,

check the following to avoid the risk of unwanted ame relay dropout :

1-1) For gas or oil ﬂames (Minipeeper):

• Low supply voltage

• Detector location

• Defective detector wiring

• Dirty viewing windows

• Faulty Minipeeper

1-2) For oil ﬂames (Photocell):

• Detector location & wiring

• Smoky flame or poorly adjusted air shutter

• Faulty Photocell

• Temperature over 165 °F (74 °C) at photocell

1-3) For gas ﬂames (Flame Rod):

• Ignition interference (A flame signal current difference with the ignition both on

and off greater than 0.5μA indicates the presence of ignition interference)

• Insufficient ground (must be at least 4 times the detector area)

• Flame lifting off burner head (ground), or not continuously in contact with the

flamerod

• Temperature in excess of 600 °F (316 °C) at the flame electrode insulator causing

short to ground.

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Amprobe ACD-14-PLUS Clamp-On-Multimeters Uživatelský manuál Strana 11