Herrmidifier Herrtronic MD Engineering Guide - Manual (Page 2)

Herrtronic ® MD Series
E n g i n e e r i n g G u i d e
2 www.herrmidifier-hvac.com
Description
The Herrtronic MD system
includes the microprocessor-
based Herrtronic MD unit, steam
distribution hardware and control
accessories. The Herrtronic MD
features an LCD display, “user
friendly” programming, system
diagnostics and the flexibility to
utilize “on/off,” “proportional” or
“proportional + integral” control!
For larger applications, these systems can be networked in
a master/slave relationship with up to 29 slave units. The
Herrtronic MD is sufficiently versatile to operate with softened
water!
Utilize the Herrtronic MD Series to meet your humidification
needs – computer rooms, telecommunication switchgear
facilities, laboratory clean rooms, etc. Consider these
outstanding features:
Styling
These aesthetically pleasing Herrtronic MD units are
constructed of 16 and 18 gauge steel finished with white
powder coat finish. All piping and wiring is routed thru the
bottom behind the integral skirt to maintain smooth lines.
Access to the disposable polypropylene cylinder is thru the
front access door. Service access to the electrical controls is
thru the front and side access doors.
Flexibility
Three sizes are available – (A) 5-30 lbs/hr., (B) 10-100 lbs/
hr, (C) 110-250 lbs/hr – to meet your requirements. Power
to these units can be 50 or 60 Hz. Single phase units are
available thru 50 lbs/hr; three phase units thru 250 lbs/hr. All
systems are ETL approved. All units are designed to run on
raw or softened water with a conductivity range of 70-1000
micromho.
Versatility
Control versatility is a distinguishing feature assuring
application success! “On/Off” control is available for less
demanding applications. Modulation can be accomplished
in (1) the “proportional” control mode with a control signal
(ohms, VDC or mADC) from an input device or “building
automation system” or (2) the “proportional + integral” mode
receiving input from a sensor (VDC or mADC).
Versatility continues with the selection of the control scheme.
For an installation with varying psychrometric conditions (i.e.
VAV, high levels of fresh air, humidification during cooling,
etc), a system with a conventional (“on/off” duct mounted)
high limit could routinely “short-cycle.” The Herrtronic MD
system will accept a proportional high limit (in addition
to the proportional control input). Typically, the MD unit
microprocessor establishes a capacity setpoint based solely
on the control input signal. In addition, the Herrtronic MD
monitors the proportional high limit input if applicable and, in
response, adjusts the capacity setpoint accordingly.
This feature minimizes the likelihood of short-cycling,
optimizing system performance! Only the external control
devices vary. This inherent versatility is only available with
the Herrtronic MD system!
Display
The informational center of the system is the LCD display
with two lines, 20 characters per line. The keyboard provides
simple access to “scroll” thru unit operating dynamics and
adjust setpoints as necessary. Certain setpoints are “secured”
and require password entry to make adjustments. All setpoints
have a built-in default value to simplify programming. The
display varies with the type of control system such that only
applicable data is provided. The Herrtronic MD display is an
on-line report card!
Diagnostics
The Herrtronic MD monitors system operations and identifies
undesirable conditions. Some “faults,” such as “current
overload,” result in system shutdown. Other “faults” indicate
potential fill or drain system problems but allow the humidifier
to continue operating. The “Master” unit will indicate the
occurrence of a “fault” in any remote unit. Herrtronic MD
diagnostics simplify required maintenance reducing both time
and expense.
Networking
The Herrtronic MD utilizes an RS-485 communications
network. A master unit can communicate with up to 29 slaves.
This represents up to 3,000 lbs/hr. of humidification capacity.
And the RS-485 communication link allows up to 4,000 feet
between the master and slave units. This integral capability is
virtually unlimited.
Accessories
Complementing the Herrtronic MD unit are a full line of
accessories. Low profile “Room Distribution Units” are
available to deliver humidification directly to the conditioned
area. The humidifier provides supply voltage and control.
Steam piping can be routed thru the back or bottom. For
critical applications, where quick guaranteed absorption is
required, consult the factory for selection of the appropriate
CS-Series steam distribution grid. Standard stainless steel
steam distributors are available in a variety of sizes and
configurations. All are designed to return condensate to
steam cylinder(s) – eliminating unnecessary condensate
piping. A variety of control devices are available for wall or
duct installation for any type of system control.
Warranty
Durability and reliability are inherent features in all Herrmidifier
products. Each Herrtronic MD system is supported by our two
(2) year warranty (applicable to all parts except the disposable
steam cylinder.