Digital Transformer Ratiometer DTR
®
Model 8510
33
5.2.4 VT/PT Continuity Test
The Continuity Test function of the DTR
®
8510 serves as a useful means
of identifying open primary and secondary windings, high resistance con
-
nections, open circuit breakers and blown fuses. When selected, the DTR
®
8510 checks for continuity between its Secondary (X) and Primary (H)
cables.
• The DTR
®
8510 will indicate OPEN for circuits >4KΩ and
CONT for circuits <4K
Ω
. Check these values. A small fraction
of transformers (High inductance or high winding Ohmic DC
resistance) may appear open.
• The instrument checks for Secondary (X) connections first. Even
if it is found open, it continues to check Primary (H) connections.
Regardless of the outcome, the instrument proceeds to perform
pre-test checks. Following the pre-test checks, if either X or H
or both were found to be OPEN, the instrument will display the
appropriate error message. Pressing the TEST button again
will start a new Continuity test (assuming the user fixed the
connection problem) again. If it passes the Continuity test, Ratio
test will be executed.
• Transformers with winding arrangement multiple, parallel paths
(e.g., Delta type) may read CONT even if one or more windings
may be OPEN.
5.2.5 CT Test
In this section, an example of running a test using the following configura
-
tion (see § 4.3 for how to configure the instrument) is shown:
• Set Date/Time: July 4, 2010. 6:00 PM
• Set values in Nameplate:
Primary Current:19920; Secondary Current: 7200
• Select Type: CT
•
Select Test Mode: Ratio
• Storage Mode: Manual
•
Set Filter: Normal
• Set Language: English
Note:
CT test does not allow a CONT/Ratio option. It only runs a Ratio test.
WARNING:
The DTR
®
Model 8510 is designed for use on de-energized
(“dead”) transformers only. Make sure the test sample is completely
disconnected from AC power and is fully discharged.
www.
ShopAEMC
.com
Shop for AEMC products online at:
1.877.766.5412
