Question

The blown-fuse LED is not indicating when no fuse is installed in the dinnector?

Answer

Insure that the polarity is correct (I.E. the hinge is on the positive side.) Install fuses and finish the circuit as if ready to operate. When the system is known operational, power down and remove the power side only fuse. The LED should come on when the circuit is complete and has a load.



There is a lot of debate over fuse protecting the neutral (grounded conductor/white) conductor of a control circuit. The rule of thumb is to treat as a standard electrical circuit with no fuse on the neutral, only the hot. OPCD's, which open the hot and neutral simultaneously, fall under this category.



However, a system with an ungrounded secondary needs to have the neutral fused. If one shorts to ground without it, the system will have a major failure.


Refer to NEC articles 240 & 250.

---

FAQ Subcategory: None

This item was last updated on 2009-10-22
Document ID: 892

---

The information provided in the AutomationDirect knowledge base is provided "as is" without warranty of any kind. AutomationDirect disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall AutomationDirect or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if AutomationDirect or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion of limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.