Siemens LMV3 series, Technical Instructions

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Technical Instructions LMV Series
Document No. LV3-1000
Section 4
Page 2 SCC Inc.
Before the LMV3 can be commissioned, certain pre-requisites must be met for the LMV3 control, the
burner, the boiler, and the boiler room. Experience has shown that if the points below are addressed
properly, commissioning will be safe, timely, and trouble-free.
Pre-Requisites for Basic LMV3 Systems
1. Burner / boiler must be in "good" condition. Burner firing head must be correct for the boiler
and the firing head must not be cracked, melted, or otherwise damaged. Other items to check
include:
a. Flame scanner tube must sight pilot and main flame correctly.
b. Refractory should not interfere with the flame scanner sighting or the flame path of the
burner.
c. For fire tube boilers, the flame should not impinge on the Morrison tube.
2. All LMV3 components (base unit, actuators, flame scanners, etc.) are mounted properly.
Particular attention should be paid to the following:
a. Actuator shaft couplings must accomplish the following:
i. Compensate for both angular and parallel shaft misalignment generated by the
mounting bracket.
ii. Have little or no backlash.
iii. Be robust enough to absorb the stall torque of the actuator without damage.
Solid (rigid) shaft couplings are not acceptable in most applications. Clamp-type
couplings that have a D-shape are preferred since these will not damage the actuator
shaft and do provide positive engagement. In linkage-less applications, actuator
couplings should be considered to be safety-related components.
NOTE: Do not couple actuator to valve / damper shaft until the direction of rotation
for the actuator is set, and the LMV3 alarm is reset. This is outlined later in the
commissioning section.
b. Actuator brackets must be rigid enough so that they do not amplify burner vibration
(diving board effect) or distort significantly when the actuator is applying maximum
torque to the valve / damper shaft.
c. When actuator is installed and coupled, ensure that all mounting hardware is tightened
adequately, and some method of thread locking is employed on the mounting hardware
(except for the coupling hardware).