The TRM-20 is Vanguard Instruments’ third generation transformer winding resistance meter. The TRM-20 is designed specifically to measure DC resistance values of transformer windings, rotating machine windings, or any dc resistance of an inductive device.
The TRM-20 features dual resistance-reading input channels that can measure two winding resistances simultaneously (primary and secondary windings of a transformer). It can provide a fast and stable reading of very large transformers by utilizing a 60Vdc power supply. The TRM-20 is capable of outputting a selectable test current from 1A to 25A.
Since the TRM-20 can accurately measure resistance values from 1 micro-ohm to 2,000 Ohms, it can be used as micro-ohm meters to measure EHV circuit breaker contact resistance, or for any low resistance measuring application. The TRM-20 can automatically demagnetize the inductive device under test, eliminating the manual task of demagnetizing the transformer core after a resistance test.
| Key Features |
| Auto-discharge circuit for operator safety |
| Demagnetizes transformer after test |
| Selectable test current from 1A to 25A |
| RS-232C, USB, and Bluetooth computer interfaces |
| Built-in thermal printer |
| Specifications |
|
TRM-20
Transformer Resistance Meter
|
|
| Features | Parameters |
| Type | Portable transformer winding resistance meter |
| Dimensions | 21” W x 17” H x 9” D
(53 cm x 43 cm x 24 cm)
|
| Weight | 33 lbs
(15.4Kg)
|
| Operating Voltage | 100 – 240 Vac, 50/60 Hz |
| Resistance Reading Range | 1 micro-ohm to 2,000 Ohms |
| Accuracy | 1 – 19,999 micro-ohms: ±0.5% reading, ±1 count
20 – 999 milliohms: ±1% reading, ±1 count
1 -2000 Ohms: ±1.5% reading, ±1 count
|
| Test Current | 1-25A in 1A increments |
| Test Voltage | 60 Vdc charging, 18V DC max during measurement |
| Resistance Channels | Two static resistance reading channels |
| Display | Back-lit LCD (64 x 128 dot graphic)
Viewable in direct sunlight and low light levels
|
| Printer | Built-in 2.5″ wide thermal printer |
| Internal Data Storage | 256 static test records
(each can contain up to 111 readings) and 120 dynamic test records
|
| External Data Storage | Up to 999 test records on external USB Flash drive |
| Computer Interfaces | RS-232C
USB
Bluetooth
|
| Safety | Designed to meet UL 61010A-1 and Can/CSA C22.2 No 1010.1092 standards |
| Environment | Operating: -10ºC to 50ºC (15ºF to +122ºF)
Storage: -30ºC to 70ºC (-22ºF to +158ºF)
|
| Humidity (Max.) | 90% RH @ 40˚ C (104˚ F) non-condensing |
| Altitude (Max.) | 2000m (6562 ft) to full safety specifications |
| Cables | One 50-foot current cable set
Two 50-foot resistance sense cable set
One LTC control cable
One ground cable
One power cord,
One RS-232C cable
One USB cable
|
| Options | Transportation Case |
Note:
Specifications are valid at nominal voltage and ambient temperature of +25˚C (+77˚F).
