GE SX TRANSISTOR CONTROL IC3645SR4U404N2 User Manual

SX TRANSISTOR CONTROL 

 

 

Page 17

 

 

 

January 2000

 

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= Control common tie 

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= DC buses feeding sensitive analog or digital hardware 

•

= All wiring connected to components associated with 

sensitive analog hardware with less than 5V signals (for 

example, potentiometers and tachometers) 

•

= Digital tachometers and resolvers 

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= Dash display cabling 

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= RS-232 cabling 

 
Note:  Signal inputs to analog and digital blocks should be 

run as shielded twisted-pair (for example, inputs from 

tachometers, potentiometers, and dash displays). 

 
4.2.2.b  High-Level Signals (Level H) 

 

High-level signals are designated as level H.  These signals 

consist of: 

 

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= Analog and digital signals greater than 15 V DC and 

less than 250 mA 

 

For example,  switch inputs connected to battery volts are  

examples of level H signals used in drive equipment 

cabling. 

 
4.2.2.c  Medium-Power Signals (Level MP) 

 

Medium power signals are designated as level MP. These 

signals consist of: 

 

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= DC switching signals greater than 15 V 

•

= Signals with currents greater than 250 mA and less than 

10A 

 

The following are specific examples of level MP signals 

used in drive equipment cabling: 

 

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= DC busses less than 10 A 

•

= Contactor coils less than 10 A 

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= Machine fields less than 10 A 

 
4.2.2.d.  High Power Signals (Level HP) 

 

Power wiring is designated as level HP. This consists of DC 

buses and motor wiring with currents greater than 10 A.  

The following are specific examples of level HP signals 

used in drive equipment cabling: 

•

= Motor armature loops 

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= DC outputs 10 A and above 

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= Motor field loops 10 A and above 

Recommended spacing (or clearance) between cables (or 

wires) is dependent  on the level of the wiring inside them. 

For correct level separation when installing cable, the 

customer must apply the general guidelines (section 

4.2.3.a), outlined below. 

 

 

The following general practices should be used for all 

levels of cabling: 

 

•

= All cables and wires of like signal levels and power 

levels must be grouped together. 

•

= In general, different levels must run in separate wire 

bundles, as defined in the different classes, identified 

above. Intermixing cannot be allowed, unless  noted by 

exception. 

•

= Interconnecting wire runs should carry a level 

designation. 

•

= If wires are the same level and same type signal, group 

those wires from one location to any other location 

together in multiconductor cables or bind them 

together with twine or zip-ties. 

•

= When unlike signals must cross, cross them in 90° 

angles at a maximum spacing. Where it is not possible 

to maintain spacing, place a grounded steel barrier 

between unlike levels at the crossover point. 

 

 

Reducing electrical noise on vehicle retrofits requires 

careful planning. Lower and higher levels should never 

encircle each other or run parallel for long distances. 

It is practical to use existing wire runs or trays as long as 

the level spacing (see section 4.2.2) can be maintained for 

the full length of the run. 

Existing cables are generally of high voltage potential and 

noise producing. Therefore, route levels L and H in a path 

separate from existing cables, whenever possible. 

For level L wiring, use barriers in existing wire runs to 

minimize noise potential. 

Do not loop level L signal wires around level H, level MP, or 

HP wires. 

 
4.2.5 RF Interference 

 

To prevent radio frequency (RF) interference, care should 

be taken in routing power cables in the vicinity of radio-

controlled devices.  

 
Section 4.2.6 Suppression 
 

Unless specifically noted otherwise, suppression (for 

example, a snubber) is required on all inductive devices 

controlled by an output.  This suppression minimizes noise 

and prevents damage caused by electrical surges.