| 摘要 |
<p>Heating elements (1A1, 2A1 etc.) are divided into two gps. assigned respectively to the heat storage mineral space (1) and hot air duct (2), served by three-phase AC supplies via separate contactors (6,7) and multipole relays (4,5). An auxiliary switch (12) in conjunction with store and duct thermostats (3, 11) provides sequential switching of the relays to supply max. current to the duct heaters (2A1-2A3), 2B1-2B3) for a period before the store heaters (1A1-1A3, 1B1-1B3) are stepped-up from half to full power.</p> |
