When to bond neutral and ground? Should you make neutral-to-ground bonds in electrical panels?

If your electrical panel is a subpanel, then NO, you do not make a neutral-to-ground connection. If your electrical panel is the first service disconnect point, AND the utility has only provided normally current carrying conductors (phase and neutral wires), then YES, you must make a neutral-to-ground connection. If your electrical panel is the first service disconnect point, and the utility has only provided normally current carrying conductors (phase and neutral wires) PLUS a ground wire, then NO, you do not make a neutral-to-ground connection. NEC 250.24(A)(5) see Handbook notes NEC 250.30(A)(1) Exception #2 NEC 250.30(A)(5) Handbook notes NEC 250.32(B)(1) Handbook notes NEC 250.142(B) See Exhibit 250.8 in the Handbook where the connection can be at the load end of the service drop Rule 10-200(1) states that objectionable currents must not flow through the grounding system during normal operations. Rule 10-204(1) states that neutral currents must not flow on the grounding system back to the transformer. Rule 10-204(1)(c) states that you are not to make connections at the consumers service that will cause neutral currents to flow on the grounding system. Rule 10-200(3) gives us recommendations for removing objectionable currents from the grounding system, including the removal of neutral-to-ground bonds in the cabinet.