Railway Signalling Electrical Point Machine
Railway Signalling Electrical Point Machine :– An electrical point machine is an electrically driven motor used for operation of points in railway yards. The rotary motion of the motor is transmitted through the reduction gears and transmission assembly and converted through linear movement of a toothed rack through a pinion. The gear rack drives switch rails to unlock, change the position from N to R or R to N and lock the switch at the end of the stroke.
Sequence of point machine operation.
1. Opening of the detection contacts.
2. Unlock the points.
3. Move the points to the desired position
4. Lock the points.
5. Close the detection contacts.
Depending up on the operating voltages
1. Low voltage .DC supplies – 24 volt DC.
2. High voltage DC supplies -110V DC.
3. High voltage AC – 380 AC.
The point machines have split series field windings.
Electrical parameters of point machine
1. Rated voltage – 110V DC.
2. Working current – 4-6 Amps.
3. Obstruction (slipping current) – 6-7 Amps.
4. Operating Time – 3 sec.
5. Type of machine – Combined type. (Operation, locking and detection)
6. Field winding – Split field
7. Field connection – Series
8. Movement of locking – Rotary type
9. Friction clutch – Self adjustable
Main parts of point machine
1. DC series split field motor within built in reduction gear unit
2. Transmission assembly
3. Throw rod, lock slides and detection slides
4. Detection and control contact switch assembly
5. Hand crank.
6. Spring loaded friction clutch.
Need for remote control of point machine:
1. To avoid voltage drop in cable cross section.
2. Contact of lever /knob/push button do not have the heavy duty current carrying capacity.
3. Track locking is to be provided to prevent point operation under wheels.
4. Point machine should be protected from over load.
5. Facility for sequential operation should be provided.
Two types of relay control units are standardized.
1. Siemens point contactor unit.
2. Point contactor unit with QBCA relays.
Visit here for more information :– https://en.wikipedia.org/wiki/Point_machine
Very simple and precise.
thanks
Dear Sir/Madam,
Good day.
Closing Date: 20th January 2019 (ASAP)
Location: Melaka
Qty: 1
Kindly quote your best price and delivery time for the following items below:
Item Description:
Technical Specifications:
Rated Voltage:120V DC -Max Power
Consumption: 0.44kW -Max Stroke: 220mm -Max Thrust: 450Kg ± 50Kg
Max Operating Time: 4 sec Max Operating Current: 5.5 Amp Number of
Contact: 4 Changeover Weight of Machine: 180 Kg -Panel Controller
Control function of movement throw bar by switch when press button (Pull
or Push) with Lamp (LED or Bulb) indication
PLEASE REPLY…URGENT REQUIREMENT
NOTE :
Please include Material, Calibration & Test Certificate where applicable.
Please provide Drawings or Catalogue where applicable.
Please quote together with Transportation Cost.
Your prompt reply is highly appreciated.
Hello Friends
Can we have the information on SIEMENS POINT MACHINES AS WELL AS
NON TRAILABLE INTERNAL LOCK POINT MACHINE TYPE JEA733127A/00
MATTER IS URGENT PLEASE
our email is [email protected] and [email protected]
Need a point interface circuit for 380V 3-phase AC point machine. Request you to share thesame.
ok