10
ECC BYPASS
In some applications, where smaller zones tend to overheat during the third (last) minute of the Energy
Conservation cycle, the ECC Bypass can be switched OFF, eliminating the third minute and leaving
dampers in the last call position (Fig. 9d).
COMPRESSOR LOCKOUT TDO 1 (STAGE 1) AND TDO 2
(STAGE 2)
All Arzel
®
circuit boards have a 4-minute compressor lockout timer (delay on break) on the compressor
circuit. When the compressor is turned off, it will stay locked out for 4 minutes. This allows the
refrigerant pressures to equalize. Time delay lockout is indicated by 2 yellow LEDs, TDO 1 (Stage 1)
and TDO 2 (Stage 2).
NOTE: Two momentary-contact Time Delay Override (TDO) switches, one for each stage, are provided
on the PC board (Fig. 9b) to speed the checkout of the HVAC system. Before using the TDO
switches you must disconnect the HVAC “R” wire to avoid short-cycling the compressor.
FAN-ON-HEAT OPERATION
Use the Fan-On-Heat switch if immediate fan operation is desired on a call for heating, such as with
electric furnaces, hot-water coils, steam coils, etc., (Fig. 9c). Fan operation is also indicated by a
green LED (G) at the zone calling and at the HVAC Output LED.
ENERGY CONSERVATION CYCLE (ECC™)
After every cycle completion, dampers will be held in place for two minutes and supply residual
conditioned air to the last zone served. After two minutes, the micro pumps continue to operate for
another minute to open all the zone dampers for a SofStart™ on the next cycle. The momentary Energy
Conservation Override (ECO) switch (Fig. 9a) will override the cycle during test or set-up operation.
Rev. 5/12/04
U.S. and Foreign Patents & patents pending.
© copyright 2004 by Arzel Zoning Technology, Inc.
Fig. 9a
Fig. 9b
Fig. 9c
Fig. 9d
