Raypak Xfiire 1000B, Инструкция по установке и эксплуатации

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In this scenario, the heater will broadcast an error and
alarm. However, it will not stop providing heat. Instead
the unit automatically reduces firing rate to minimum firing
rate. If flow is indeed null or low, the heater has other
protection algorithms such as Outlet Max, and Max Delta T
Protection, which will shut down the heater if these values
are exceeded.
Cascade Flow Offset (If optional flow meter
is installed)
In a cascade configuration, the master XFiire heater will
only allow the next unit in the cascade to operate when
the observed flow is double the minimum flow requirement
of the next unit in the cascade. This is to overcome any
pressure drop when enabling the second heater. It is
expected that the flow will drop significantly when the
isolation valve of the next heater in the cascade is opened.
Because pressure drop may vary depending on several
specific conditions of each job site, the Cascade Flow
Offset provides the ability to fine tune the minimum flow
requirement in a cascade configuration. Adjusting the
Cascade Flow Offset will affect the call of the next unit in
the cascade (speed up or delay the call). This setting is
located within the Adjustment Menu in system settings.
The default value is "0" with range of -25 gpm to +15 gpm
(-95 lpm to +57 lpm).
Example: If the cascade consists of 3 heaters where each
heater has a MIN flow condition of 40 gpm (151 lpm), and
the Cascade Flow Offset value is "0" (factory default),
the master heater requires seeing a minimum 80 gpm
(302 lpm) before attempting to open the second heater
insulation valve (upon a continued call for heat). Adjusting
the Cascade Flow Offset value to "-5" results in the master
heater seeing a minimum flow equal to [40 – 5 =35 gpm
(132 lpm) for each heater] or 70 gpm (264 lpm) total before
attempting to open the second heater isolation valve.
The following fuctions of the VERSA IC are
applicable only if an optional flow meter is
installed.
∆T Protection Zones
The ∆T Protection Zones are a function of the VERSA
IC which monitors flow, firing rate, and anticipated
∆T based on the type of fluid (water or water/glycol
concentration) being heated to determine if the heater
is functioning properly.
The XFiire product includes multiple checks to ensure
the safe performance of the unit. If the flow meter
reading is determined to be inaccurate, the unit will still
find the optimum point of operation based on the ∆T. If
heater flow is indeed below what is being reported by
the sensor, the ∆T will increase in proportion to the flow
discrepancy.
The XFiire will adjust firing rates using dynamic
thresholds called “∆T zones”. These zones are (1) Flow
Warning Zone, (2) Hold Firing Rate Zone, and (3) Min
Firing Rate Zone, described in the following sections.
Flow Warning Zone
The Flow Warning Zone is considered a warning. The
service light will flash, no alarm will be triggered, and a
warning error will be broadcast and recorded. The flow
warning indicates that the ∆T is higher than the expected
value given a specific flow and firing rate.
The Flow Warning Zone operates in conjunction with the
user-defined ∆T Offset – see Troubleshooting, Section
9 for more details. If the ∆T continues to increase and
exceeds the Flow Warning Zone, the heater will enter
the Hold Firing Rate Zone.
Hold Firing Rate Zone
In the Hold Firing Rate Zone, the control will hold
modulation regardless of the flow reading. The firing
rate will be held at the current firing rate in an attempt to
prevent the ∆T from increasing further. If the ∆T drops
below this zone, heater operation will release to PID
control. If the ∆T continues to increase, the control will
enter the Min Firing Rate Zone.
Min Firing Rate Zone
If all other attempts to prevent the ∆T from increasing
fail, the firing rate will drop to minimum firing rate as
a last attempt to prevent a ∆T fault. If this action is
effective, the ∆T will drop and the heater will attempt
to find the optimum point of operation. However, if this
action is not successful and the ∆T continues to climb,
and the MAX ∆T threshold is exceeded, and the burner
is forced to cycle.