Daikin EWAP200MBYNN [241/452] Lead lag control

ESIE05-07 Functional Control for a Standalone Unit

Part 2 – Functional Description 2–45

2.10 Lead-lag Control

Introduction This function only applies on units with double circuit.

The lead-lag mode determines which circuit starts up first in case of a capacity demand. It prevents

the unit from always starting up the same circuit.

Possible modes:

P Automatic: The controller decides whether circuit 1 or circuit 2 starts up first.

P Manual C1 > C2: Circuit 1 starts up before circuit 2. If circuit 1 is deactivated due to a failure, circuit

2 will start up instead.

P Manual C1 < C2: Circuit 2 starts up before circuit 1. If circuit 2 is deactivated due to a failure, circuit

1 will start up instead.

Remark: the different modes can be selected in the user settings menu.

Lead-lag hours in

automatic mode

When the lead-lag control is done automatically, the software calculates the differences in operation

time between the circuits. When this time is higher than the preset lead-lag hour value, the start

sequence of both circuits is swapped.

The limit values of the lead-lag hours are the following:

P lower limit: 100 hours

P upper limit: 1000 hours

P default value: 1000 hours

Remark: This value is important for maintenance purposes. It should be set high enough so that the

two compressors (if double circuit) do not require maintenance at the same time and that at least one

compressor can remain constantly active.

Equal start up

compressors

P Yes: both circuits will go up in capacity alternating.

P No: the leading circuit will go to full capacity before the lagging circuit can start up.

ESIE05-07.book Page 45 Wednesday, October 11, 2006 10:42 AM