supply of relay qna1.relay qna1., supply of relay, ac immune, plug in type, style qna1, dc neutral line, 24 v dc, 12f-4b contacts, metal to carbon, with plug board, retaining clip and connectors conforming to brs : 931a, irs s 60, irs s 34 and irs s 23 ( as applicable ) . the interlocking for this unit shall be abdfh. , supply of relay, ac immune, plug in type, style qna1, dc neutral line, 24v dc, 8f-8b contacts, metal to carbon, with plug board, retaining clip and connectors conforming to brs : 931a, irs s 60, irs s 34 and irs s 23 ( as applicable ) . the interlocking code for this unit shall be abdgh. , supply of relay, ac immune, plug in type, style qna1, dc neutral line, 24v dc, 8f-8b contacts, metal to carbon, with plug board, retaining clip and connectors conforming to brs : 931a, irs s 60, irs s 34 and irs s 23 ( as applicable ) . the interlocking code for this unit shall be abdgh. , supply of relay, ac immune, plug in type, style qna1, dc neutral line, 24v dc, 8f-8b contacts, metal to carbon, with plug board, retaining clip and connectors conforming to brs : 931a, irs s 60, irs s 34 and irs s 23 ( as applicable ) . the interlocking code for this unit shall be abdgh. , supply of relay, ac immune, plug in type, style qna1, dc neutral line, 24v dc, 8f-8b contacts, metal to carbon, with plug board, retaining clip and connectors conforming to brs : 931a, irs s 60, irs s 34 and irs s 23 ( as applicable ) . the interlocking code for this unit shall be abdgh.