Operating instructions

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There are two basic types of SSR modulation: SSR
modulation with contactors, and 100% SSR
modulation.
SSR modulation with contactors
With SSR modulation with contactors, the operation
of the unit is the same as it is with TP Modulation. In
this scenario, one of the cycling contactors is
replaced with an SSR. The SSR is now the device
that carries out all of the cycling duties. The
contactors will always be either on or off. Any TP
cycling that is needed will be handled by the SSR
stage.
This provides two distinct advantages over standard
TP modulation. First, an SSR can turn on and off
much faster than a contactor can. Therefore, as the
unit modulates around a demand signal, tighter
control is achieved because the cycle time on an SSR
system is factory-set at one second. This means that
every second, the controller can adjust the on and off
times on the SSR to very closely track the desired
demand.
The second major advantage over standard TP
modulation is reliability. With a solid state device
like an SSR, component wear and tear is almost
nonexistent when compared with an
electromechanical device such as a contactor.
Therefore, with the SSR doing all of the heavy
cycling work, the life expectancy of the contactors is
extended.
100% SSR modulation
The ultimate in electric humidifier modulation is 100%
SSR Modulation. With this type of control, all heat
stages are controlled by SSRs. This allows the output
of the humidifier to track the actual demand very
closely because all heat stages can now cycle on and
off at the rapid SSR cycle rate.
With 100% SSR modulation, a contactor is still
provided in series, with the SSR device as an
additional safety feature. This contactor is energized
any time there is demand on the humidifier, and
remains energized until the demand is satisfied. In
this way, if there is a failure in the SSR device, the
contactor is there as a backup to shut the humidifier
down.
Modulation types: SSR modulation.
Operation
Operation:
SSR modulation