360 Auxiliary EPC
Contents
1. 18 Check for leaks Restore the GC to operating condition 1 Plug in the GC and turn it on 12 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual Auxiliary EPC 360 Replacement procedures 2 Press Aux 3 Aux 4 or Aux 5 to access the desired channel If your manifold is correctly installed you will see the following display PNEUMATIC AUX 3 Pressure 0 x Off Init time 0 00 Rate 1 off T An actual flow value is displayed when the gases are off or not connected This is not an error After the gases are connected and the detector is operational the actual flow values will be equal to the setpoint values 3 Ifthe display reads Aux not installed recheck your cable connections 4 Zero the pressure sensors a b C Make certain that no gases are connected to your manifold Press Options and scroll to Calibration Aux pressure Scroll to Aux 3 zero and press On Scroll to Aux 4 zero and press On Scroll to Aux 5 zero and press On Jun 2001 Detectors 13 of 16 Agilent 6890 Gas Chromatograph Service Manual 360 Auxiliary EPC Replacement procedures 5 Connect the source gas lines to the manifold See Figure 360 10 AUX WII th Wate OW A PRESSURE PROGRAMMABLE 4300P 100 Figure 360 10 Gas line connections 6 Restore gas pressures and leak check all fittings Changing an auxiliary channel frit 1 Locate the2. gases at their supply then turn off the main power switch and unplug the power cord 1 Remove the pneumatics cover the RFI shield the detector cover the electronics cover the right side cover and the top rear panel 2 Remove the gas supply tubing from the present manifold See Figure 360 1 Disconnect gas lines OR Disconnect gas lines PRESSURE PROGRAMMABLE Type 1 manifold installed before January 1999 Type 2 manifold installed after January 1999 99 Figure 360 1 Remove the gas connections 3 Remove the Torx T 20 mounting screw from the front of the manifold See Figure 360 2 4 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual Auxiliary EPC 360 Replacement procedures Slot for tubing Torx T 20 mounting screw Figure 360 2 Removing the auxiliary flow manifold 4 Disengage the tubing from the slots in the chassis so that the gang fitting on the manifold can be removed easily See Figure 360 2 Caution Always hold the Type 2 manifold by its support bracket to avoid damaging board components 5 Unlock the manifold s ribbon cable from the pneumatics control board and detach the connector The adjacent ribbon cable may have to be removed as well 6 Remove the one Torx T 20 screw holding the gang fitting on the manifold See Figure 360 3 Caution Do not lose the O rings when you remove the gang fitting Jun 2001 Detectors 5 of 16 Agilent 6890 Gas Chro
3. 360 Auxiliary EPC Theory of operation WARNING The auxiliary EPC channels are controlled by a pressure setpoint To work properly there must be adequate flow resistance downstream of the pressure sensor The auxiliary channel pneumatics manifold provides a frit type restrictor for each channel Four frits are available Frit Marking Flow Resistance Part no Blue Dot High 19234 60660 Red Dot Medium 19231 60770 Brown Dot Low 19231 60610 None brass tube Zero G1570 20540 The Red Dot frit is in all three channels when the instrument is shipped The figures on the next two pages show approximate pressure flow relationships for the three Dot frits assuming there is no significant additional resistance downstream of the frits If the Zero resistance frit is installed the user must provide flow resistance downstream and generate the pressure flow relationships When hydrogen is used dangerously high flows are possible if insufficient flow resistance is provided downstream of the supply tube Always use either the High Blue Dot or Medium Red Dot frit with hydrogen External flow restrictor Type 2 manifold Use an external flow restrictor part no G1530 80380 on each auxiliary EPC channel to be used for a flammable gas i e hydrogen The restrictor prevents excessive gas flow in the event of a leak in the manifold or its input fitting External flow restrictor Jun 2001 Detectors 1 of 16 Agilent 6890 Gas Ch
4. block that connects the three gas outlet tubes for the auxiliary channels to the pneumatics module 2 Remove the screw that holds the block to the pneumatics module Pull the block free of the module and rotate it so that the frits are on top Aux 4 frit Aux 5 frit Aux 3 frit Flow block Aux 4 outlet Aux 5 outlet 14 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual Auxiliary EPC 360 Replacement procedures 3 Pull the frit to be changed out of the block Also remove the O ring that seals it 4 Place an O ring on the new frit Place the O ring frit combination in the block 5 Reconnect the block to the pneumatics module Tighten the screw firmly Jun 2001 Detectors 15 of 16 Agilent 6890 Gas Chromatograph Service Manual 360 Auxiliary EPC Replacement procedures 16 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual
5. fold 7 Route the ribbon cable to the right side of the manifold assembly as shown in Figure 360 5 Then slide the manifold and bracket assembly into the Aux slot until the bracket seats flush against the end of the rails See Figure 360 6 L A UANL 4300P10C0 Figure 360 5 Routing the ribbon cable Jun 2001 Detectors 9 of 16 Agilent 6890 Gas Chromatograph Service Manual 360 Auxiliary EPC Replacement procedures Route tubing along this path Bracket is flush with Check for interference carrier rails Attach gang fitting My 8 Route the gas tubing behind the manifold over the top of the chassis and through the slots as shown in Figure 360 2 and Figure 360 6 9 Connect the ribbon cable to the mating connector on the pneumatics board This is behind the connector for the back detector and faces up See Figure 360 7 10 Secure the manifold in place using the Torx T 20 mounting screw See Figure 360 2 Connector for auxiliary manifold Connector for back detector manifold Figure 360 7 Auxiliary and back detector connectors 11 Ifthe detector cable is in the way remove it temporarily while you connect the Aux cable Arrange the cable to keep it away from the valves and keep it from being pinched against the manifold 10 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual Auxiliary EPC 360 Replacement procedures Caution Overtigh
6. matograph Service Manual 360 Auxiliary EPC Replacement procedures Remove screw and gang fitting yi MTN PRESSURE mi LA HA I P PROGRAMMABLE Manifold installed before January 1999 Manifold installed after January 1999 WARNING WARNING Caution Figure 360 3 Removing the gang fitting Installing a type 2 manifold If you are replacing a Type 1 manifold with a Type 2 manifold order the accessory kit G1570 60720 This kit contains a new pneumatics control board bracket that is required for the Type 2 manifold See also Replacing the PCB bracket Hydrogen gas is flammable and potentially explosive Before replacing the manifold turn off the hydrogen gas at the source Before proceeding turn off the oven and any heated zones and let them cool down Turn off all detector gases at their supply then turn off the main power switch and unplug the power cord Always hold the manifold as shown below to avoid damaging board components 6 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual Auxiliary EPC 360 Replacement procedures 1 While holding the manifold by the black plastic frame as shown below slip the label through the slot in the mounting bracket and align the bracket holes over the gas fittings Hold manifold by the black plastic frame Slip label tag through the slot in the bracket FPD shown 2 Finger tighten three 7 16 inch hex nuts over the fitti
7. ngs to hold the bracket in place It is very important that you do not tighten the nuts yet See Figure 360 4 Jun 2001 Detectors 7 of 16 Agilent 6890 Gas Chromatograph Service Manual 360 Auxiliary EPC Replacement procedures Finger tighten nuts Do not use a wrench FPD shown above Mounting bracket Gang fitting installs here Apply blank label 7 16 inch hex nuts Ribbon cable Label ID tag through slot TRAE 4300P 1000 PRESSURE PROGRAMMABL in bracket Figure 360 4 Bracket mounted onto the manifold 3 Peel the blank label from its backing and paste it on the mounting bracket over the screw heads See Figure 360 4 4 Ifyou need to change one or more auxiliary channel frits do so now See the Agilent 6890 GC Operating Manual CD ROM 8 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual Auxiliary EPC 360 Replacement procedures 5 Ifthe tubing from the gang fitting bends to the left reshape it so that it bends up and back from the block as shown in Figure 360 6 6 Insert the gang fitting through the cutout in the manifold bracket and install it onto the new manifold assembly so that the tubing runs back and away from the fitting e Be sure that the three O rings are in place e Be sure the left tube clears the inner edge of the bracket See Figure 360 6 Tighten the screw on the gang fitting until the gang fitting touches the mani
8. romatograph Service Manual 360 Auxiliary EPC Theory of operation Pressure requirements for AUX EPC flow restrictors with air nitrogen or helium ambient conditions 25 C 14 7 psia LATTA i l 19234 60660 blue dot I E Vg 60770 E Vg J pe 19231 60610 ee brown dot 0 10 0 100 0 1000 0 Gas flow in mL min 60 50 Minimum source pressure 40 psig 20 10 30 0 1 2 of 16 Detectors Jun 2001 Agilent 6890 Gas Chromatograph Service Manual Auxiliary EPC 360 Theory of operation Pressure requirements for AUX EPC flow restrictors with hydrogen ambient conditions 25 C 14 7 psia i Hl 19234 60660 blue dot ws Hil ee 19231 60770 source red dot pressure psig i ll jae 60610 jae dot r lll 0 0 1 1 0 10 0 100 0 1000 0 Gas flow in mL min Jun 2001 Detectors 3 of 16 Agilent 6890 Gas Chromatograph Service Manual 360 Auxiliary EPC Replacement procedures Replacement procedures For general replacement procedures for a Type 1 manifold see Pneumatics Control Module Removing the auxiliary manifold type 1 or type 2 WARNING Hydrogen gas is flammable and potentially explosive Before replacing the manifold turn off the hydrogen gas at the source WARNING Before proceeding turn off the oven and any heated zones and let them cool down Turn off all detector
9. tening may cause hazardous leaks Tighten the hex nuts exactly as described below 12 Use a wrench to tighten the 7 16 inch hex nuts 3 4 turn only 13 Using a pair of needle nosed pliers remove the top rear panel cutout for Auxiliary Also remove any cutouts needed to access other manifolds or accessories installed in the GC See Figure 360 8 Insert tip of pliers here Back inlet Front inlet Front detector Auxiliary Left most screw slot Back detector Figure 360 8 Top rear panel cutouts 14 Place the new top rear panel on its left most mounting screw Use the screw as a hinge and angle the panel while sliding each manifold ID tag through its cutout in the panel working from left to right When all the tags are through the panel finish installing the panel on the GC Jun 2001 Detectors 11 of 16 Agilent 6890 Gas Chromatograph Service Manual 360 Auxiliary EPC Replacement procedures 15 Attach the Aux EPC label to the top of the pneumatics chassis as shown in Figure 360 9 below Attach label here Gas outlet block Figure 360 9 Attaching the Aux EPC label 16 Install the RFI shield the pneumatics cover and the detector top cover 17 If using hydrogen or other flammable gases install an external flow restrictor part no G1530 80380 on each fitting that will be used for a flammable gas External flow restrictor installed and ready for connection to gas line
Download Pdf Manuals
Related Search