Gas Valve Proving System

Transcription

1 Gas alve Proving System GY DU... Series... SO 001 The DU... gas valve proving system is designed for use in gas-fired plant equipped with two safety shutoff valves. During each startup cycle, the control unit automatically programs the valve proving test and, in the event of a leak, prevents burner startup. Use The DU... control unit is designed to provide automatic gas valve proving (leakage test) based on the pressure proving principle. t is for use in gas-fired plant with or without vent pipe to the atmosphere. For plants without vent pipe, where D/DG regulations apply, refer to the hints given on «onnection examples with vent pipe to the atmosphere». Gas valve proving is initiated automatically with every burner startup using one or two standard pressure monitors, either prior to burner startup, during the pre-purge time, if it lasts at least 0 s, immediately after the controlled shutdown, or on completion of the burner control's control program, e.g. on completion of the postpurge time The valve proving test is based on the two-stage pressure proving principle: first, the valve on the mains side is tested by evacuating the test space and by monitoring the atmospheric pressure in it. Then, the valve on the burner side is checked by pressurizing the test space and by monitoring the gas pressure. f the pressure increases excessively during the first test phase (Test 1), or decreases excessively during the second test phase (Test, the control unit inhibits burner startup and goes to lockout. n that case, the lockout reset button lights up to indicate the fault. emote indication of the fault is also possible. program indicator, which stops whenever a fault occurs, indicates which of the two valves is leaking. The DU... can be reset either on the unit itself or with an electric remote resetting device. andis & Staefa pril 1, 1 1/

2 echanical design The control unit is of plug-in design. Housing and plug-in base are made from impactproof and heat-resistant plastic material. The housing accommodates: The synchronous motor of the sequence switch complete with gear train and step action sequence switch The camshaft with 1 non-adjustable cams The program indicator at the head of the camshaft One main and one auxiliary relay The lockout relay which can be electrically reset from a remote location and which provides the functions «ockout» and «esetting» The unit fuse with a spare fuse ll electrical components are interconnected via printed circuits. The plug-in base carries the following terminals: connection terminals auxiliary terminals (nos. «1» and ) earth terminals neutral terminals (prewired to terminal, the neutral input) The following knockout holes are available for the cable entry: 1 knockout holes for the cable entry by means of cable glands, at the side and at the bottom of the base threaded knockout holes at the side for cable entry glands Pg Plug-in base and terminals are designed such that the erroneous plugging in of a unit with the same housing, which is not suited for use with the relevant burner, is made impossible. isible in the transparent lockout reset button, the program indicator informs service staff about the programming sequence, the type of fault and the point in time the fault occurred, using easy-to-remember symbols. Ordering ontrol unit for gas valve proving, without base For 0-0, 0-0 Hz DU. For 0-1, 0-0 Hz DU. Plug-in base G Technical data ains voltage 0-1 % % Perm. current rating of control terminals 0-1 % % to D 00 ains frequency 0 Hz - %...0 Hz + % equired switching capacity of pressure switch 1 min., 0 Power consumption - during the test. ounting position optional - during burner operation. Degree of protection P0 Prefuse (externally) T/00 eight Unit fuse T,H0 to 1 control unit approx. 00 g adio interference protection to D 0 base approx. g Perm. input current at terminal 1 continuous to D 00 nvironmental conditions: conformity - Transport 1-- ccording to the directives of the uropean ommunity limatic conditions class K lectromagnetic compatibility Temperature / G include. /1 Humidity < % r.h. Gas appliance directive 0/ echanical conditions class missions Operation 1-- mmunity 00- limatic conditions class K Temperature Humidity < % r.h. ondensation, formation of ice and influence of water are not permitted. / pril 1, 1 andis & Staefa

3 ode of operation To carry out the first phase of the valve proving test, called «Test 1», there must be atmospheric pressure in the length of pipe between the two valves to be tested. n plants with a vent to the atmosphere, this pressure is available if the valve proving test is conducted prior to or during the pre-purge time. n plants without a vent pipe, atmospheric pressure is made available as the control unit opens the valve on the burner side during the time «t». f the valve proving test is performed after the operation of the burner, the valve on the burner side after the controlled shutdown can be kept open until «t» has elapsed, thus reducing the pressure in the test space and making certain its gas content is burnt off in the combustion chamber during the post-purge time. prerequisite for this procedure is an appropriate control program of the burner control as provided by andis & Staefa burner controls type F..., F..., GK... or... The test space is closed off after it has been evacuated. During the first test phase (Test 1) which follows immediately, the control unit checks if the atmospheric pressure in the test space is maintained using the pressure monitor. f the valve on the mains side is leaking, causing the pressure to rise above the switching point of the pressure monitor, the control unit initiates an alarm and goes to lockout. The program indicator then stops and indicates «Test 1». f the pressure does not increase because the valve closes correctly, the control unit immediately programs the second test phase (Test. To do this, the valve on the mains side is pressurized («filling» of test space). During the second test phase, the pressure may not fall below the switching point of the pressure monitor due to a leak of the valve on the burner side. f it does, the control unit goes to lockout again, thus inhibiting burner startup. On the successful completion of the second test phase, the control unit closes the internal control loop between terminals and (circuit path: terminal - contact «ar» - terminals and - contact - terminal ). This control loop is usually included in the start control loop of the burner control. fter the control loop has been closed, the programming mechanism of the control unit returns to its start position where it switches itself off. During these «idle steps», the position of the control contacts of the programming mechanism remains unchanged. andis & Staefa pril 1, 1 /

4 Program and lockout indicator hen the unit goes to lockout, the programming mechanism stops and also the position indicator fitted to the spindle of the mechanism. The symbol that stops above the reading mark not only indicates during which test phase lockout occurred, but also after how many programming steps within the test phase (1 step =. seconds). eaning of symbols: Start position = operating position n plants without a vent valve: evacuation of test space through opening of the valve on the burner side Test 1 «Test 1» with atmospheric pressure (valve proving test on the mains side) Filling the test space through opening of the valve on the mains side Test «Test» with gas pressure (valve proving test on the burner side) dle steps until programming mechanism switches itself off Operating position = start position for the next valve proving test n the event of lockout, all terminals receiving voltage from the control unit are deenergized, except terminal, which is used for lockout indication. fter the unit has been reset, the programming mechanism automatically returns to its start position and immediately reprograms a new valve proving test. ote: do not press the reset button for more than seconds. ontrol program after a power failure power failure prior to evacuating the test space does not cause the program sequence to change. f a power failure occurs after the evacuation, the valve proving test will not be continued when power is restored, but the programming mechanism first returns to its start position to reprogram the complete proving test. / pril 1, 1 andis & Staefa

5 alculation of leakage rate escaping from a length of pipe Q eck = (P G -P w P atm x x x t Test where: Qeck in dm/h Permissible leakage rate in dm or liters per hour PG in mbar Overpressure in pipe section between the valves to be tested, at the beginning of the test phase P in mbar Overpressure set at pressure monitor (usually set to 0 % of the gas mains pressure) Patm in mbar bsolute pressure ( mbar normal pressure) in dm olume of test space confined by the valves to be tested, including the space in the valves themselves ttest in s Duration of proving time xample PG = 0 mbar P = 1 mbar Patm = mbar ny valve leakage rate exceeding 0 l/h causes the control unit to go to lockout =. dm ny valve leakage rate exceeding 0 l/h causes the control unit to go to lockout ttest =. s ote: the volume of pipe section between the gas valves to be checked and overpressure Pw set on pressure monitor must be selected such that the maximum permissible gas leakage rate Qeck will not exceed the rate specified in the local regulations. ontrol program t s vacuation of test space t. s nterval from start to energizing of main relay t1. s First test phase with atmospheric pressure t s Filling the test space t. s Second test phase with gas pressure t. s Total duration of valve proving test to the enabling of the burner t0. s unning time of programming mechanism until it switches itself off in the operating = start position («idle steps») andis & Staefa pril 1, 1 /

6 onnection diagram 1) K SK 1 1 S a b a1/ a b a b a b H br1 ar1 1 1 a X b X a b tm. Gas P b a b a a b ar 1) K1 1 br ~ S DU egend for the entire data sheet, 1, Gas valves controlled to empty the test space larm signal «eaking valve» ain relay with contacts «ar...» S uilt-in fuse Gas valve controlled to fill the test space ockout relay with contacts «br...» ent valve, normally open; closed during valve proving test from the beginning of «Test 1» Pressure monitor for valve proving test (does not replace the gas pressure monitor used to signal lack of gas) Safety shutoff valve, normally closed; optional K... ockout reset button K emote lockout reset button Gas pressure monitor (for lack of gas) H uxiliary relay with contacts «hr...» 1 uilt-in lockout warning lamp DU ontrol unit ir pressure monitor... Fan (: pre- and post-purge) ontrol thermostat or pressurestat, e.g. boiler control thermostat Pipe orifice, its diameter must be determined such that in the event of a leaking pilot gas valve, the pilot flame cannot afterburn on completion of the nd safety time so that the presence of the main flame cannot be simulated SK ontrol contact (initiation of valve proving test) S Synchronous motor of programming mechanism T Delay off time relay: the time should be set to approx. t (t min....t max.) of the burner control imit thermostat or pressure monitor 1) Do not press K for more than seconds xpanding flame or interrupted pilot burner operation / pril 1, 1 andis & Staefa

7 Sequence diagram arning notes The electrical wiring must comply with local and country-specific standards and regulations! The DU... must be completely isolated from the mains before performing any work on it! The DU... is a safety device. t is therefore not permitted to open, interfere with or modify the unit! heck wiring carefully before putting the unit into operation! heck all safety functions when putting the unit into operation or after replacing a fuse! nsure protection against electric shock hazard on the unit and at all electrical connections through appropriate mounting! lectromagnetic emissions must be checked from an application point of view! The regulations and standards covering the specific application must be observed! ll installation and commissioning work must be carried out by qualified personnel! n the geographical areas where D standards are in use, the installation must be in compliance with D requirement, particularly with the standards D/D 00 and 0! ondensation and ingress of humidity must be avoided! gnition cable must always be laid separately, observing the greatest possible distance to other cables! andis & Staefa pril 1, 1 /

8 onnection examples with vent pipe to the atmosphere using burner control F... For other connections, refer to the wiring diagram of the burner control. Proving test following immediately the controlled shutdown a/0 1 F..., S.0 F..., S.0 1 a/0 P K DU K DU 1 onnection examples with vent pipe to the atmosphere using burner control F1... For other connections, refer to the wiring diagram of the burner control. Proving test following immediately the controlled shutdown F1... a1/0 F1... a1/0 1 P 1 K DU K DU / pril 1, 1 andis & Staefa

9 onnection examples with vent pipe to the atmosphere using burner control G.../.../... For other connections, refer to the wiring diagram of the burner control. G.../.../... 1 a0/0 H 1 / DU Proving test following immediately the controlled shutdown G.../.../... 1 a0/0 H P / DU nstallations with vent pipe to the atmosphere DU DU 1 s01/0 andis & Staefa pril 1, 1 /

10 onnection examples with vent pipe to the atmosphere using burner control F, F, GK or programming unit... For other connections, refer to the wiring diagram of the burner control. Proving test during pre-purge time (0 s min.) F1 1 / a0/0 F / a0/0 F1... GK... 1 / F1... GK / K DU K DU alve proving with two pressure monitors G Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be set to the minimum gas pressure permitted during the proving test. f this pressure is not reached during the test, the control unit goes to lockout. Pressure monitor for the gas valve proving test with atmopheric pressure. This pressure monitor must be set to the maximum gas pressure permitted during the proving test with atmospheric pressure. f this pressure is exceeded during the test, the control unit goes to lockout. G and must be overload-proof up to the gas pressure level. G 1 a0/0 nstallations with vent pipe to the atmosphere / pril 1, 1 andis & Staefa

11 onnection examples with vent pipe to the atmosphere using burner control F, F, GK or programming unit... Proving test both during the pre-purge time (0 s min.) and immediately after the controlled shutdown in plants with a vent pipe to the atmosphere. On delay of relay d > s. a/0 F / F1... GK / d K DU Proving test following immediately the controlled shutdown F1 1 / a/0 F1... GK... 1 / K DU andis & Staefa pril 1, 1 /

12 onnection example without vent pipe to the atmosphere (suitable for all countries) using burner control F, F, GK or programming unit... Proving test following immediately the controlled shutdown in plants without vent pipe. alve or «1» remains open after the controlled shutdown until the start of the first test phase is reached in order to evacuate the test space and to burn off the gas contained in it in the combustion chamber during the after-burn time. F1 1 / a1/0 F1... GK... 1 / K DU 1 alve proving with two pressure monitors G Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be set to the minimum gas pressure permitted during the proving test. f this pressure is not reached during the test, the control unit goes to lockout. Pressure monitor for the gas valve proving test with atmopheric pressure. This pressure monitor must be set to the maximum gas pressure permitted during the proving test with atmospheric pressure. f this pressure is exceeded during the test, the control unit goes to lockout. G and must be overload-proof up to the gas pressure level. G 1 a0/0 nstallations without vent pipe to the atmosphere 1/ pril 1, 1 andis & Staefa

13 onnection examples without vent pipe to the atmosphere using burner control F... (cannot be used where D/DG and TD1 regulations are in force) For other connections, refer to wiring diagram of the burner control. Proving test following immediately the controlled shutdown 1 a0/0 F..., S.0 F..., S.0 1 a1/0 P K DU K DU onnection examples without vent pipe to the atmosphere using burner control F1... For other connections, refer to wiring diagram of the burner control. Proving test following immediately the controlled shutdown a/0 a/0 F1... F P K DU K DU 1 andis & Staefa pril 1, 1 /

14 onnection examples without vent pipe to the atmosphere using burner control G.../.../... For other connections, refer to wiring diagram of the burner control. a/0 G.../.../... 1 H / DU 1 Proving test following immediately the controlled shutdown a1/0 G.../.../... 1 / P H DU 1 nstallations without vent pipe to the atmosphere DU DU s0/0 1 1/ pril 1, 1 andis & Staefa

15 onnection examples without vent pipe to the atmosphere using burner control F..., F..., GK... or programming unit... For other connections, refer to wiring diagram of the burner control. Proving test during pre-purge time (0 s min.) F1 1 / a/0 F / a/0 F1... GK... 1 / F1... GK / K DU 1 K DU alve proving with two pressure monitors G Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be set to the minimum gas pressure permitted during the proving test. f this pressure is not reached during the test, the control unit goes to lockout. Pressure monitor for the gas valve proving test with atmopheric pressure. This pressure monitor must be set to the maximum gas pressure permitted during the proving test with atmospheric pressure. f this pressure is exceeded during the test, the control unit goes to lockout. G and must be overload-proof up to the gas pressure level. G 1 a0/0 nstallations without vent pipe to the atmosphere andis & Staefa pril 1, 1 1/

16 onnection examples without vent pipe to the atmosphere using burner control F..., F..., GK... or programming unit... and SKP0... with expanding flame burners For other connections, refer to wiring diagram of the burner control. Proving test during pre-purge time (0 s min.) F a/0 / F a/0 / F1... GK / F1... GK / T K DU K DU alve proving with two pressure monitors G Pressure monitor for the gas valve proving test with gas pressure. This pressure monitors must be set to the minimum gas pressure permitted during the proving test. f this pressure is not reached during the test, the control unit goes to lockout. Pressure monitor for the gas valve proving test with atmopheric pressure. This pressure monitor must be set to the maximum gas pressure permitted during the proving test with atmospheric pressure. f this pressure is exceeded during the test, the control unit goes to lockout. G and must be overload-proof up to the gas pressure level. G 1 a0/0 The air pressure for the SKP (P) must be sufficiently high to open the SKP0, although the burner s air damper is closed. f this is not observed, the DU... control unit will go to lockout when performing Test1 nstallations without vent pipe to the atmosphere DU SKP0 0/0 / pril 1, 1 andis & Staefa

17 Dimensions Dimensions in mm DU... with base G... 1, 1, 1 1,, 1 1 1,, m0/0, G...,x, 0 1,,, 1, , 1,, 1, 1 1, 1 1,, 1, 1,,x, m01/0, 1, 1, 0 1, 1 andis & Gyr Produktion (Deutschland) GmbH andis & Staefa pril 1, 1 /