TR-7546 family units are designed for safe operation of medium voltage cast resin / dry type transformer. It is suitable for control room as well as marshalling box installation and is built for long
and trouble-free operation under extreme conditions of service associated with transformer.
Three numbers of user settable set-points can be used to control the cooling fan, to warn the user of high temperature and to shut down the transformer in case of excessive heating. Four nos. of Pt-100
RTD sensors allows the user to monitor the temperatures of windings plus one other critical point on the transformer like core.
These relays are programmed to note and store maximum temperature of the winding. Facility extends to recall this information and to clear it for fresh recording. The maximum Temperature is
saved such that it can be recalled even after the power for the controller fails.
General Specifications
Inputs: 4 RTDs (Pt-100, IEC 60751)
No. of Set-points : Three (Fan, Alarm & Trip)
Indication range : - 20 0C to 250 0C
Set point range : 20 to 220 0C
Accuracy : ± 1 0C
Dead Band : Fan & Trip : 8 0C, Alarm : 5 0C
Display Speed : 4 secs
Displays : One 0.3" for channel no,
Three 1/2" for temperature.
LED Indications
- Sensor Fault
- Fan Status
- Alarm Status
- Trip status
- Max temps are being displayed
- Programming mode on
- Fan On manually or because of Auto fan exerciser
- Display hold to single channel
Relay Operation
Fault : Will energize on detecting sensor fault or
when in programming mode.
If specifically asked, we can provide units with
“Electric fail fault” provision, whereby this relay turns
on after few seconds of power-on and de-energizes
on detecting sensor fault. In this case, this relay
turns off even for electric fail.
Fan : Will energize if any channel’s temperature
reaches fan set point. This relay will also turn on as
per fan exercise set timings, if this function is
enabled.
Alarm : Will energize if any channel’s temperature
reaches alarm set point.
Trip : Will energize if any channel’s temperature
reaches trip set point.
Mechanical Specifications
Dimensions : 96 (H) x 96 (W) x 150 (D) mm
Cut-out : 92 X 92 mm (+ 1 mm).
Mounting: Flush Panel mounting.
Weight: 550 gms approx. (unpacked)
Enclosure: Noryl.
Electrical Specifications
Supply Voltage: 90-270VAC/DC , 40-400 Hz
(Optionally 20-50VAC/DC)
Outputs :
- 4-20mA output, corresponding to 0
to 200 0C, max. load 300 ohms,
linearity 0.5% w.r.t. local indication
Terminals:
Screw-cage combicon,
- for RTDs, suitable for one
1 mm2 wire.
- for All other, suitable for one
2 mm2 wire.
Contact ratings: For Resistive load 5A @ 240VAC,
0.2A @ 220VDC
Power consumption:
Max. 15VA
Insulation: 100 Mohm or more at 500 VDC
between Earth and terminals.
2KV rms at 50 / 60 Hz for 1 minute
(port to port).
Environment
Ambient: -20 to 70 0C. R.H.: 95% max
non -condensing.
Storage Temp.: -20 to 85 0C.
Test Conditions: Amb. Temp. 27 ±5 0C.
Shock: 15g, Half sine, in 3 orthogonal
planes
