Rinnai Manifold Electronic Control System - Mecs And Cascade - Rinnai HD28E Operation & Installation Manual

Manifold Pack Principle Of Operation
Cold water enters system through cold inlet pipe is heated by water heater(s) and exits through hot pipe. Dead-leg
systems will deliver preset temperature as per dipswitch or controller settings.
Rinnai Heavy Duty Units require a minimum of either 1.5 l/min or 2.4l/min (depending on which water heater is
used) per heater before they can operate. If this is not achieved they will not fire. When there is an expected
scenario that results in a lower flow per heater a staging system is required. Rinnai Manifold Packs come as
standard with either MECS (Manifold Electronic Control System) or Cascade staging systems. Staging will control
the flow through each water heater, increasing the chance of minimum flow rate being achieved. It does this by
measuring the flow rate passing through the turbine of each heater. It will drive the geared motor inside the HD
unit shut in heaters that are not required to operate, therefore increasing the flow rate through the remaining
heaters. Extra heaters are fired as the flow rate increases. The staging control system also rotates the sequence
of operation to share the load across all heaters to maximise life expectancy.

RINNAI MANIFOLD ELECTRONIC CONTROL SYSTEM - MECS AND CASCADE

Rinnai Heavy Duty Gas Fired Continuous Flow Water Heaters can be manifolded together, (up to 25 individual
water heaters), by connecting them in parallel to enable a far greater hot water flow rate than is possible with a
single unit.
MECS and Cascade are integrated control systems unique to Rinnai linking each water heater. Their primary
function is to monitor demand and activate water heaters accordingly.
The key advantages to using a staging control system are as follows:
•
Very high flow rates/volumes made possible by linking individual heaters in parallel.
•
Load shared across linked heaters ensuring even wear rates.
•
Inherent redundancy in the event of a failed water heater(s).
•
Reduced gas consumption resulting in increased economy.
•
Unsurpassed water temperature consistency.
Refer to the separate installation instructions provided with the control system.
Rinnai
INSTALLATION HANDOVER MANUAL
19 Commercial Manifold Pack OIM