GE SX Series Installation And Operation Manual

GE SX Series Installation And Operation Manual Manual pdf 17 page image

DIAGNOSTIC STATUS CODESSX TRANSISTOR CONTROL Page 17Revised May 2003 Control common tie DC buses feeding sensitive analog or digital hardware All wiring connected to components associated withsensitive analog hardware with less than 5V signals (forexample, potentiometers and tachometers) Digital tachometers and resolvers Dash display cabling RS-232 cablingNote: Signal inputs to analog and digital blocks should berun as shielded twisted-pair (for example, inputs fromtachometers, potentiometers, and dash displays).4.2.2.b High-Level Signals (Level H)High-level signals are designated as level H. These signalsconsist of: Analog and digital signals greater than 15 V DC andless than 250 mAFor example, switch inputs connected to battery volts areexamples of level H signals used in drive equipmentcabling.4.2.2.c Medium-Power Signals (Level MP)Medium power signals are designated as level MP. Thesesignals consist of: DC switching signals greater than 15 V Signals with currents greater than 250 mA and less than10AThe following are specific examples of level MP signalsused in drive equipment cabling: DC busses less than 10 A Contactor coils less than 10 A Machine fields less than 10 A4.2.2.d. High Power Signals (Level HP)Power wiring is designated as level HP. This consists of DCbuses and motor wiring with currents greater than 10 A.The following are specific examples of level HP signalsused in drive equipment cabling: Motor armature loops DC outputs 10 A and above Motor field loops 10 A and above4.2.3. Cable Spacing GuidelinesRecommended spacing (or clearance) between cables (orwires) is dependent on the level of the wiring inside them.For correct level separation when installing cable, thecustomer must apply the general guidelines (section4.2.3.a), outlined below.4.2.3.a General Cable SpacingThe following general practices should be used for alllevels of cabling: All cables and wires of like signal levels and powerlevels must be grouped together. In general, different levels must run in separate wirebundles, as defined in the different classes, identifiedabove. Intermixing cannot be allowed, unless noted byexception. Interconnecting wire runs should carry a leveldesignation. If wires are the same level and same type signal, groupthose wires from one location to any other locationtogether in multiconductor cables or bind themtogether with twine or zip-ties. When unlike signals must cross, cross them in 90°angles at a maximum spacing. Where it is not possibleto maintain spacing, place a grounded steel barrierbetween unlike levels at the crossover point.4.2.4 Cabling for Vehicle RetrofitsReducing electrical noise on vehicle retrofits requirescareful planning. Lower and higher levels should neverencircle each other or run parallel for long distances.It is practical to use existing wire runs or trays as long asthe level spacing (see section 4.2.2) can be maintained forthe full length of the run.Existing cables are generally of high voltage potential andnoise producing. Therefore, route levels L and H in a pathseparate from existing cables, whenever possible.For level L wiring, use barriers in existing wire runs tominimize noise potential.Do not loop level L signal wires around level H, level MP, orHP wires.4.2.5 RF InterferenceTo prevent radio frequency (RF) interference, care shouldbe taken in routing power cables in the vicinity of radio-controlled devices.Section 4.2.6 SuppressionUnless specifically noted otherwise, suppression (forexample, a snubber) is required on all inductive devicescontrolled by an output. This suppression minimizes noiseand prevents damage caused by electrical surges.