The INCON® 1250-LTC Programmable Load Tap Changer (LTC) Position Monitor relays critical position information between a distribution transformer LTC and the LTC controller, enabling utilities to run their transformers as efficiently as possible.


With over 40 years of proven service in over 33,000 utility transformers around the globe, the 1250-LTC does so much more than just monitor tap position. It is a vital tool that utilities use to predict transformer maintenance and prevent the failure of their LTC’s.


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Ensure transformer loads are balanced.

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Regulate line voltage by adjusting feeder voltage.

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Reduce power costs by providing minimum line voltage to the customer.

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Deploy predictive transformer maintenance with intelligence.

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The 1250-LTC is a highly advanced solid-state instrument, which measures the absolute position of a Synchro Transmitter connected to the LTC drive shaft. It provides a user-definable visual digital display indication of tap position as well as both analog and digital signal outputs suitable for a variety of monitoring and control applications. LTC position monitors can feed data directly into a SCADA and MODBUS system to help utilities balance loads, regulate line voltage, reduce costs, and deploy predictive maintenance.

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In addition to basic LTC tap position, the 1250-LTC monitors several additional important characteristics related to LTC movement. Programmable alarm options help utilities automate transformer maintenance planning. Check out these examples:

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It is important for an LTC to pass through the neutral tap occasionally.If it doesn’t the reversing switch may become sticky and inoperable. The 1250-LTC has a programmable alarm that tells the utility if it has been too many days since the LTC has passed through the neutral tap.​

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The 1250-LTC can be programmed to close one of its relays upon completion of each tap change. This can be used as a feedback acknowledgment that the requested tap change was successful.​ If the acknowledgment isn't made, it can be a good indication that maintenance is required.

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Most LTC’s rotate about 9 to 11 degrees with each tap change. The 1250-LTC can measure in increments of 1/10th of a degree. A special feature of the 1250-LTC is its ability to monitor small discrepancies in tap position. A programmable limit can be set to give an alarm when the discrepancy in tap position reaches the limit. Inaccurate tap position can be an early indicator of wear in the LTC mechanism or possible impending failure.

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If, for some reason, the LTC controller gets a faulty voltage reading, the LTC can run away in one direction; a serious condition that can effect transformer operation. The 1250-LTC has a programmable alarm that can be used to cut power to the drive motor if it detects too many tap changes in one direction.

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In the course of its life, an LTC may move up and down through the same few taps. As a result, these taps will have much more wear than the rest of the contacts. The 1250-LTC keeps a count of how many tap changes were made up to and down to every tap. This data helps utilities plan maintenance and replacement of the LTC contacts.


Installing INCON® LTC Position Monitoring in an existing transformer is easy regardless of make, model, or setup.

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  1. The 5-wire Syncro Transmitter is mechanically coupled directly to the transformer’s LTC drive mechanism.

  2. Vital LTC position data is transmitted via AC signal to the LTC Position Monitor. The AC signal is 0-90 VAC and in-phase with the surrounding AC systems making it immune to noise.

  3. Inside the substation control room, the signal from the Synchro Transmitter is interpreted by the LTC Position Monitor as an angle, which is precisely converted to a tap position by firmware.

  4. The LTC position is fed to a central dispatch center via analog output signal through a Remote Terminal Unit (RTU).

  5. Signals from a network of LTC Position Monitors can be fed into a utility’s SCADA system, providing remote LTC position information for an entire network of transformers.




The Franklin Electric Grid Solution Technical and Field Support Teams are here to assist with training, installation, and support. Our Field team will come to your site for training or installation supervision and our Support Center staff is available to assist with troubleshooting, warranty processing, and software installation support.

All Models

Resolution (1250B & 1250-LTC) ± 0.001% of full scale or 6 arc minutes
Accuracy +/-0.02% of full scale, maximum (0.01% typical)
Temperature Drift +/-0.01% per °C
Operating Temperature 0 ° to 55 °C
Humidity 10% - 90% non condensing
Weight 24 ounces
Voltage 117 +/- 10%
Frequency 47 - 63 Hz
Load 8 Watts, maximum
Display Type 5-digit LED
Digit Height 0.56 inch (14.2 mm)
Viewing Distance 23 feet
Decimal Point (1250B) Field programmable
Optional Analog Outputs +/- 1 mA, 0-1 mA, 0-2 mA, 4-20 mA (requires 15 to 24 VDC external loop power)
Compliance 10 Volts (0-1 mA, ± 1mA, 0-2 mA)
500 Ohms (4-20 mA)
5 mA (0-10 VDC, ± 10 VDC) 1511-LTC
Resolution 12 bits (± 0.025% of full scale)
Optional Hi/Lo Relay Contact Rating 3A @ 125/250 VAC (resistive), 30 VDC
Communication Options RS-232 (ASCII)
RS-485 Full Duplex (MODBUS)




The 1250-LTC is a versatile programmable position monitor. Its main application is for Transformer LTC position monitoring, but its non-linear conversion table gives it the ability to convert non-linear rotary motion into a linear scale for additional applications.



U = Output Options

0 =  0-1 mA

1 =  ±1 mA

2 =  0-2 mA

4 =  4-20 mA

W = Control

R =  Hi/Lo Relay Limits

I =  Input Isolation


Y = Comm. Options

S =  RS-232 Serial 

M =  RS-485 MODBUS



The Synchro Transmitter is the preferred position indicating technology where reliability, rugged design, and accurate absolute position data are critical. The Transmitter is available with a surge suppression option and a mounting bracket. Designed for use with 1250B and 1250-LTC, solid-state INCON Programmable Position Monitors.

Model Description
1292 Synchro transmitter
1292K Synchro transmitter with "L" mounting bracket
1292S Synchro transmitter with surge protection circuit
1292KS Synchro transmitter with mounting bracket and surge protection circuit
1945 15 VDC Loop Power Supply (For 4-20 mA Analog Output)



  • Extra-rugged right-angle "L" bracket assembly option for secure, parallel-to-surface mounting
  • Circuit board terminations option for easy wiring connections, without crimp-lugs
  • Surge suppression option for transient protection
  • Highly accurate output signal corresponds to rotary position
  • Absolute position sensor, no zero-position loss after power-down
  • Reliable, rugged, long-life transmitter


  • Very fine resolution-extremely accurate and reliable
  • Does not require re-zeroing or periodic calibration
  • Excellent signal/noise immunity
  • Stable over time and temperature
  • Virtually unlimited life
  • Can be retrofited to older LTC’s without existing synchros


  • Ideal for power, process, and industrial equipment applications
  • Transformer load tap changers
  • Equipment position
  • Hydro-electric spillway & generator gates
  • Valves of all kinds
  • Machine tools
  • Cable reels and hoists
  • Screw conveyors, and more


Model 1292 1292K 1292S 1292KS
Mounting Synchro flange "L" bracket Synchro flange "L" bracket
Wire Terminations Ring lugs (provided) Ring lugs (provided) Phoenix terminal blocks Phoenix terminal blocks
Wire Size 22-18 AWG 22-18 AWG 28-14 AWG 28-14 AWG
Surge Protection None None 150 Volt, 14 mm Metal Oxide Varistors (3 ea.) 150 Volt, 14 mm Metal Oxide Varistors (3 ea.)
Fuse Protection None None 5A Fast Blow 5A Fast Blow




The "Quick Connect" Flexible Coupling is designed for unique mounting and connecting applications. It makes retrofits to older equipment easy with standard lengths and coupling diameters to fit most LTC applications.

Model Description
1293-KIT Universal coupling kit, includes an 18 inch flexible shaft and one each 0.250", 0.375" and 0.500" couplings




X = Shaft Length

9 =  9 inches

18 =  18 inches

X =  Custom length, X inches


Y = Coupling Diameter

250 =  0.25 inch

375 =  0.375 inch

500 =  0.50 inch



  • Quickly connects to all Model 1292 Synchro Transmitters
  • Secure, positive attachment to an LTC shaft
  • Two standard lengths
  • Three standard coupling sizes
  • Custom designs available


Provides easy Synchro Transmitter retrofit to voltage regulators.

Model Description
1265-5.75 5.75" dial face diameter transmitter retrofit kit
1265-6.25 6.25" dial face diameter transmitter retrofit kit
1265-7.19 7.19" dial face diameter transmitter retrofit kit
1265-7.62 7.62" dial face diameter transmitter retrofit kit
1265-8 8" dial face diameter transmitter retrofit kit
1269-10 10 foot (3 m) interface cable
1269-20 20 foot (6.1 m) interface cable
1269-50 50 foot (15.2 m) interface cable
1269-100 100 foot (30.4 m) interface cable
  • The 1265 does NOT include lightening / surge protection. If needed, MOV protection should be installed in a nearby junction box.



  • Some Load Tap Changers and Voltage Regulators can not be equipped with Selsyn® synchro transmitters. This problem can be easily solved with the INCON model 1265 Transmitter Retrofit Kit.
  • For those applications where there is no easy way to retrofit a transmitter to the LTC drive mechanism, INCON offers the Model 1265 Transmitter Retrofit Kit.
  • The 1265 retrofit kit replaces the glass lens on the local indicator dial.
  • The 1265 is designed for use with the INCON model 1250B Programmable Position Monitor, which displays the LTC position and can transmit a proportional analog signal to SCADA.
  • The Kit comes complete with a Synchro, mounted on a clear Lexan Dial and a two-pronged engagement arm that tracks the position of the Dial Indicator needle.
  • The Kit also includes the mating connector pieces, to facilitate assembly of a field wiring cable, although it is recommended that the factory-assembled cable be used.


  • Provides accurate Tap Position Status in remote locations.
  • Proven reliability with many in Utility & Industrial operations for over 20 years.
  • Does not interfere with mechanical draghand operation.
  • Highly reliable and accurate (1292) synchro transmitter is included.
  • Saves manual reporting time and money.
  • Maintenance free.
  • Can be retrofited to older LTC’s without existing synchros.


Power input 115 Volts AC
Output signal 0 to 90 Volts AC
Isolation 900 Volts, rotor to stators
Temperature range -40 to 158 °F (-40 to 70 °C) 92% humidity (non-condensing)
Display type Clear, Lexan dial face 5.75, 6.25, 7.19, 7.62 or 8.00 inches
Depth to front surface 4.0 inches (10.2 cm) with cable off


The INCON® 15 Volt DC regulated Power Supply is used with INCON® Programmable Load Tap Changer (LTC) Position Monitors that are ordered with the 4-20 milliamp analog output option.

Model Description
1945 15 VDC Loop Power Supply (For 4-20 mA Analog Output)
  • This product is a Class 1 power supply and requires the chassis to be connected to earth ground at end application. Use 700 °C iron for soldering input connections. Tolerance for 230 VAC operations is +15% to -10%.



  • VDE transformer construction (full rated to 50 °C)
  • + 0.05% regulation - foldback / current limit
  • T.C. burned-in to MIL - 883 Lev. B
  • UL recognized / CSA certified
  • Chassis notched for AC input
  • Over voltage protection on 15V output
  • 100/120/220/230-240 VAC power
  • Industry standard frame size
  • This product is a Class 1 power supply and requires the chassis to be connected to earth ground at end application.


  • The five-wire input to the power supply provides four voltage ranges: 100/120/220/230-240. Extended low line tolerance provides additional drop out margin in areas where line voltages are marginal. Inputs must be fused.
  • Convection cooling is adequate where nonrestricted airflow is available. When operating in a confined area, moving air or conduction cooling is recommended.
  • The power supply has inherently low conducted and radiated noise levels for most system applications that meet the requirements of FCC Docket 20780 for Class A equipment without additional noise filtering.


The 1945 power supply is designed to meet or exceed requirements of the following specifications: IEC 380, IEC 435, VDE 0730 Part 2, VDE 0804, ECMA-57, CEE 10 Part 2P, UL 1012, CSA 22.2 No. 143, CSA 22.2 No. 154. Specifically, field terminal to terminal spacing is 5.25 mm with 9.0 mm creepage to other metal. Leakage current is less than 5.0 mA and dielectric withstanding voltages are 3750 VAC input to chassis. 3750 VAC input to output and 300 VDC output to chassis.


AC Input 100 / 120 / 220 / 230-240 VAC, ±10%, 47-63Hz (derate output current 10% for 50 Hz operation). Fuse at: 0.5 / 0.25 amps for 100 -120 / 220 - 240 VAC.
Fuse at 0.5 / 0.25 amps for 100 -120 / 220 - 240 VAC
DC Output 12 - 15 V (± 5%) Adjustable
Line Regulation ± 0.05% for a 10% line change
Load Regulation ± 0.05% for a 50% load change
Output Ripple 5.0 mV PK-PK maximum
Transient Response ≤ 50μs for a 50 to 100 % load change
Short Circuit and Overload Protection Automatic current limit / foldback
Over Voltage Protection Not Available
Remote Sensing Separately connect S+ and S- terminals to the load  to regulate the voltage at the load
Stability ± 0.3% for 24 hour period after 1 hour warm-up
Temperature Rating 0 °C to 50 °C full-rated derated linearly to 40% at 70 °C
Temperature Coefficient ± 0.03%/°C maximum
Efficiency 55%
Vibration Per ML-STD-8100 method 514.3 category 1 procedure I
Shock Per ML-STD-8100 method 516.3 procedure III
Weight 2 lbs (1 kg)
Shipping Weight 3 lbs (1.5 kg)



The AC Line Power Conditioner provides output that is clean, voltage stabilized, and virtually free of transient spikes and noise. It is designed to be used with the model 1250-LTC or 1250B Programmable Position Monitors and their synchro transmitter.

Model Description
1932 AC line power conditioner



  • Regulates line voltage
  • Filters harmonic noise for increased stability, accuracy and reliability
  • Includes lightning arrestors and surge protection


Input Voltage 105 to 135 VAC @ 60 Hz
Output Voltage 115 VAC @ 60 Hz ±3%
Load 10 VA (Min.) to 25 VA (Max.)
Temperature range -13 to 158 °F (- 25 to 70 °C)
Fuse External 5 Amp (Max) not supplied but required


The Model 1924-20VA is a Step-Down Transformer specifically chosen to power the INCON Programmable Position Monitor systems (Model 1250, 1292 and 1511) from 230/240VAC, 50/60Hz, as typically found in Europe and Asia.

Model Description
1924-20VA Step down transformer


Designed specifically for the 1250 panel instrument products, the 1280 offers an inexpensive way to protect all inputs and outputs on these instruments from high voltage surge and spike damage.

Model Description
1280 Surge Protection Module For 1250, 120 VAC


The model 1994 is a weather-proof enclosure designed for the INCON model 1250B, 1250-LTC and  1511-LTC Programmable Position Monitors.  This NEMA 4X rated ABS plastic enclosure can be opened at each section to allow for easy access to field wiring.  When closed, each section is sealed with an EDPM rubber seal. The crystal-clear top cover allows easy reading of the instrument’s display and hinges open for installation and programming of the instrument.

Model Description
1994 NEMA 4x Enclosure