Faulty band heaters?

[CFL]

I was replacing some blown fuses that feed band heaters on a vessel and I checked each circuit to ground and found that all but one band is "shorted" to ground. I automatically assumed they were all bad and told the customer to order new ones. Their maintenance guy was called and told me I wasn't testing it correctly. I measured .5 ohms hot to ground as one example.
I replaced some damaged wiring as requested but left the bands alone. They tell me it's normal to this type of reading. Does anybody have experience with this that could give me a little more insight. Thanks.

 

[hurk27]

I was replacing some blown fuses that feed band heaters on a vessel and I checked each circuit to ground and found that all but one band is "shorted" to ground. I automatically assumed they were all bad and told the customer to order new ones. Their maintenance guy was called and told me I wasn't testing it correctly. I measured .5 ohms hot to ground as one example.
I replaced some damaged wiring as requested but left the bands alone. They tell me it's normal to this type of reading. Does anybody have experience with this that could give me a little more insight. Thanks.

Unless this is an inductive type band heater, or a low voltage resistive type heater below 30 volts, all current carrying parts of the heater must be electrically isolated from the vessel, other wise you will have current flowing on this vessel and a shock hazard.

427.3 requires us to follow all other parts of the code unless specifically amended in the 427 article, which will require no current on the grounding.

If this is a grounded type service, then I would assume this is what took out the fusses, but the problem is if a heater was to go to ground mid stream in the element, it would still function, but could run much hotter then designed, and it would be a shock hazard since you have current flowing over your grounding.

Wana bet this is a case where you did the trouble shooting, and there going to do the replacing?

 

[CFL]

Unless this is an inductive type band heater, or a low voltage resistive type heater below 30 volts, all current carrying parts of the heater must be electrically isolated from the vessel, other wise you will have current flowing on this vessel and a shock hazard.

I thought it was a resistive type heater, but I'm really not sure. The voltage is 480v and each band is 2750 watts. An engineer did tell me they were inductive. How do I distinguish the two types? I figured that an inductive band would encircle the vessel but I guess don't know the theory behind it.

If this is a grounded type service, then I would assume this is what took out the fusses, but the problem is if a heater was to go to ground mid stream in the element, it would still function, but could run much hotter then designed, and it would be a shock hazard since you have current flowing over your grounding.

Wana bet this is a case where you did the trouble shooting, and there going to do the replacing?

It is a grounded service and I assumed the same thing, that the heaters would still function but be much hotter. I removed the outer covers of the vessel and there was the evidence of overheating. The wires leading off the terminals were all damaged from heat and many of them were burned in half. That is what they had me replace, which they claim to be normal, and this is only after 2 months of service.