I am new to this forum so please be gentle. I have a customer who owns a welding shop with a tig and mig welder in use at all times. these machines are causing havoc with his phone system and and his computer system. I realize the problem is most likely from square wave noise on the neutral, but can anyone tell me the most efficient way to get rid of this problem?
Power Quality In Welding Shop
- Thread starter yelco
- Start date
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ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Move the phones to a shielded data line, DSL, cat-5, etc. A slow-voltage tech can install shielded, cat-5 phone cable, or you can use shielded welding cable. However, improper/inconsistent bonding of DSO shields can alter welder impedance/performance.
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Is the phone system on an isolation transformer or a UPS? Electronic phone systems should always be on an decent UPS or some form of protected power. (The $100 ones usually don't count as decent.) How about the computers? Also, does the phone system have a -good- ground? Not just the line cord's ground.
Installing shielded cable for the phones might help, but usually unless the phone lines run right next to a welding machine, it won't do much good. It'll help less for network (Ethernet) lines as they're already transformer isolated at both ends (it's part of the design), so they already reject the common-mode noise.
Installing shielded cable for the phones might help, but usually unless the phone lines run right next to a welding machine, it won't do much good. It'll help less for network (Ethernet) lines as they're already transformer isolated at both ends (it's part of the design), so they already reject the common-mode noise.
ramsy
Roger Ruhle dba NoFixNoPay
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
Hey guys, at what point does a phone systems POTS line merge with Welding equip. power?
If noise leaks from wall outlets, how does it get into a phone that only needs the POTS line, or a Class II receptacle transformer. If it was plugged into the wall, wouldn't that 6vdc ~300mA coil isolate the phone from 120vac office noise.
If noise leaks from wall outlets, how does it get into a phone that only needs the POTS line, or a Class II receptacle transformer. If it was plugged into the wall, wouldn't that 6vdc ~300mA coil isolate the phone from 120vac office noise.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
ramsy said:
good question.
robbietan
Senior Member
- Location
- Antipolo City
Hey guys, at what point does a phone systems POTS line merge with Welding equip. power?
If noise leaks from wall outlets, how does it get into a phone that only needs the POTS line, or a Class II receptacle transformer. If it was plugged into the wall, wouldn't that 6vdc ~300mA coil isolate the phone from 120vac office noise.
the noise could be travelling through ground. I have seen these phone lines use a single ground rod for themselves, not connected to the power line ground. or these phone lines could be grounded to the receptacle ground.
If noise leaks from wall outlets, how does it get into a phone that only needs the POTS line, or a Class II receptacle transformer. If it was plugged into the wall, wouldn't that 6vdc ~300mA coil isolate the phone from 120vac office noise.
the noise could be travelling through ground. I have seen these phone lines use a single ground rod for themselves, not connected to the power line ground. or these phone lines could be grounded to the receptacle ground.
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