RM-111 Operations Manual
Application 5
Application 5
11.0 Testing an Electronic Standard with Taps (Potential Gating)
Equipment Needed:
• RM-111 Automated Comparator
• RM or RD Primary Reference Watthour Standard
• Electronic standard to be tested
• RM-1R Electronic/Mechanical Potential Relay
Test Steps:
1. Make the appropriate connections so that the standard(s) under test (DUTs) and the RM or RD
Primary Reference Standard(s) are powered from the same voltage and current source.
2. Apply test voltage, current and auxiliary power. At this point, the RM or RD Reference
standard(s) should be counting.
• Connect all standard pulse outputs to the RM-111.
• The RM or RD Primary Reference Watthour Standard will output pulses continuously once
auxiliary power, voltage, and current have been applied.
• Older generation induction and electronic standards display “equivalent revolutions” instead
of “watthours.” The Kh of these older standards is usually 0.6 watthours per equivalent
revolution when tested at 120 volts, 5.0 amps at 1.0 power factor. To determine the proper
number of output pulses from the reference standard, use the following as a guide. If the
reference standard for this test is a Radian standard that outputs 100,000 pulses per watthour,
multiply 100,000 times the Kh of 0.6 which results in 60,000. Enter this value as the “number
of reference standard pulses to count” for a one revolution test of the D.U.T. To select the
number of pulses to count for the 1.0; 12.5;15.0 and 50.0 amp taps, refer to section 20 of this
manual for the Kh at each of these taps and multiply that fi gure by 100,000. Example: for the
12.5 amp tap: 100,000 x 1.5 = 150,000.
3. Turn on the RM-111 and select the TEST SETUPS menu option. From the TEST SETUPS
menu, select STANDARD TEST. To create a new test setup, select Create. To edit an existing test
setup, select Edit. To delete a test, select Delete. The Test Setup screen contains all the necessary
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