Siemens or Ldu11.323A27 Leak Detection Valve Proving System Oil Gas Burner Controller for Automatic Shutoff Valves

Product Description

Siemens OR LDU11.323A27 Leak Detection Valve Proving System Oil Gas Burner Controller For Automatic Shutoff Valves

Product Description

The LDU11... valve proving system is designed for use with shutoff valves in connection with gas burners and gas appliances. In the event of inadmissible leakage, the system prevents the burner from starting up. The LDU11... system conforms to the requirements of EN1643 covering automatic shutoff valves for use with gas burners and gas appliances to EN161. The LDU11... and this Data Sheet are intended for use by OEMs which integrate the valve proving system in their products.

Detailed Photos

Use

The LDU11... is designed for automatic gas valve proving (leakage test) based on the pressure proving principle. It is for use on gas-fired combustion plant with or without vent pipe to atmosphere. In the case of plants with no vent pipe where EN standards apply, the notes given in «Connection examples without vent pipe to atmosphere» must be observed. Used in connection with 1 or 2 commercially available pressure switches, valve proving is automatically initiated with every burner startup, either - prior to

burner startup - during the prepurge time if it lasts a minimum of 60 seconds - immediately after a controlled shutdown, or - on
completion of the burner control's control sequence, e.g. at the end of the postpurge time The valve proving test is based on the 2-stage pressure proving principle: 1. The valve on the mains side is tested by evacuating the test space and by monitoring the atmospheric pressure in it. 2. The valve on the burner side is checked by pressurizing the test space and by monitoring the gas pressure. If the pressure increases excessively during the first test phase called «Test1», or decreases excessively during the second test phase called «Test2», the LDU11.... will inhibit burner startup and initiate lockout. In that case, the lockout reset
button will light up to indicate the fault. Remote indication of the fault is also possible. A program indicator, which stops whenever a fault occurs, indicates which of the valves is leaking. The LDU11... can be reset either on the unit itself or via an electric remote reset facility.

 

Function

 

During the first phase of the valve proving test called «Test1», atmospheric pressure must exist in the length of pipe between the valves to be tested. In plants with a vent pipe to atmosphere, atmospheric pressure is available if the valve proving test is made prior to or during the prepurge time. In plants without vent pipe, atmospheric pressure is made available as the valve proving system opens the valve on the burner side during evacuating the test space (t4). If the valve proving test LDU11... is performed after burner operation, the valve on the burner side after the controlled shutdown can be kept open until evacuating the test space (t4) has elapsed, thus lowering the pressure in the test space and making certain its gas content is burnt off in the combustion chamber during the postpurge time. Prerequisite for this procedure is a suitable control program of the burner
control as provided by burner controls type LFE..., LFL..., LGK... or LEC...

The test space is closed off after evacuation. During the first test phase «Test1», which then follows, the LDU11... checks with the pressure switch if the atmospheric pressure in the

test space is maintained. If the valve on the mains side is leaking, causing the pressure to rise above the switching point of the pressure switch, the LDU11... will trigger an alarm and initiate lockout. The program indicator then stops to indicate «Test1».

If the pressure does not increase because the valve closes correctly, the LDU11... continues its program with the second test phase «Test2». For that purpose, the valve on the mains side is opened during filling the test space (t3) so that the test space is
pressurized («filling» the test space). During the second test phase - if the valve on the burner side is leaking - this pressure must not fall below the switching point of the pressure switch. If it does, the LDU11... will initiate lockout also, thus preventing the burner from starting up.

On successful completion of the second test phase, the LDU11... closes the internal control loop between terminals 3 and 6 (circuit path: terminal 3 - contact (ar2) - terminals 4 and 5 - contact III - terminal 6).
This control loop is normally included in the burner control's start control loop.

After the control loop has been closed, the
programming mechanism of the LDU11... returns to its start position to switch itself off. During these so-called idle steps, the positions of the programming mechanism's control contacts remain unchanged.

PRODUCT SPECIFICATIONS

item	value
Place of Origin	Germany
Brand Name	Siemens
Model Number	LDU11.323A27
Product Name	Siemens OR LDU11.323A27 Oil Gas Burner Controller Leak Detection Valve Proving System For Automatic Shutoff Valves
Adapter burner	gas burner
Weight	4
Power supply	220-240V AC 50/60HZ
Degree of protection	IP40
Color	Black
Delivery time	payment after about 2 days
Shipping Term	DHL/UPS/Fedex/TNT
Usage	gas burner accessories
After Warranty Service	Video technical support

Siemens OR LDU11.323A27 Leak Detection Valve Proving System Oil Gas Burner Controller For Automatic Shutoff Valves

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Siemens OR LDU11.323A27 Leak Detection Valve Proving System Oil Gas Burner Controller For Automatic Shutoff Valves