Bob explains Honeywell's 7800 Burner Control - With the 7800’s now in substantial use, questions had been requested with the aid of customers that are not really replied, or not included at all, in honeywell’s literature.? this data-tec will try and answer a number of the ones questions. A.? that relies upon.? if, on energy-up, the initiate tolerances aren't met within the 10 seconds, a “keep” length is started.? if the tolerances are met during this “hold” period, the ten-2nd length re-starts offevolved to make certain all tolerances are met for 10 seconds.? the “keep” period can last as long as four minutes most.? if tolerances aren't met in four mins, a lockout will arise. A.? no.? the provoke length is activated while the relay is “to start with” powered.? the 7800’s need to be powered thru a fused disconnect so they are powered always.? the 7800’s will also input initiate at any time if the strength supply is going out of tolerance. A.? at some point of the initiate duration, all of the 7800 collection of controls look at the voltage and frequency of the power furnished.? the power need to be within positive tolerances for the manage to remain on line.? all of the 7800’s are rated 120vac, 60 hz.? the tolerances for voltage are plus 10, minus 15 (102 to 132 volts) and plus zero, minus 10 for frequency (51 to 60 hz).? there are 50 hz controls available.
A.? yes, but they're for export and might no longer be used on this country.? all old 208 to 240 vac systems need to be upgraded to 120 vac.? each insurance organization and approval frame inside the united states of americaa. Requires that flame protection systems be 120 vac, one aspect grounded. A.? all 7800’s are no less than 10 seconds.? there has been an exception to this.? the authentic rm7890’s had handiest a -2nd initiate period, but on account that october of 1994, the rm7890’s were revised and also have a ten 2nd minimum provoke duration, like all of the relaxation of the 7800 collection.